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Plug-in device, phone app or built-in car data: which tracking method?
How plug-in devices, phone apps and automaker data differ in accuracy, privacy and hassle, and what changes if you swap cars or phones mid-program.
Choose the method that matches how you actually drive and what you are willing to share. A phone app is the most common and the easiest to start, but it follows you rather than the car, so it can record trips you did not drive. A plug-in device is tied to one vehicle and does not need your phone, but it cannot see phone use and must be installed, kept plugged in and returned. Built-in car data needs no app or device at all, and it is the hardest to control because the data starts with the automaker, not the insurer.
Insurers offer different mixes, and some programs allow only one method. This article compares the three on accuracy, privacy and practicality, covers the mistakes each one makes, and explains what happens to your score if you change cars or phones. Program details are as published by the insurers in November 2026 and vary by state.
The three methods side by side
| Plug-in device | Phone app | Built-in car data | |
|---|---|---|---|
| Where the sensors are | A small module in the car's diagnostic port | Your phone's GPS, accelerometer and gyroscope | The car's own modem and computers |
| Follows | One car | One person | One car |
| Can score phone use | No | Yes | Depends on the automaker |
| Setup | Mailed to you; plug in; later return | Download, sign in, grant permissions | Consent in the automaker's app or screen |
| Main accuracy risk | Another driver uses the car | Passenger or non-car trips recorded as yours | Consent and data flow you cannot easily see |
| Main privacy question | What the device records, including location | What the app can see on a phone that holds far more | What the automaker shares, and with whom |
| If you switch cars | Device moves or is replaced | Usually carries over | Starts over with the new car's data |
Several details in that table come from specific programs described below. Treat the column labels as the typical case, not a rule.
Plug-in devices: simple hardware, narrow view
A plug-in device connects to the vehicle's diagnostic (OBD-II) port, usually under the dashboard near the steering column. It records speed and motion and sends trip data to the insurer wirelessly.
Progressive describes the arrangement in its plug-in device terms (last updated March 2022). The device records speed and location using GPS, time, the vehicle identification number, G-force on some devices, and when it is plugged in and unplugged, and sends the data wirelessly. Miles driven and rates of acceleration and braking are calculated from speed and time. The terms also say that where you drive is not used in determining your personalized rate. Progressive's separate test-drive terms describe the same family of devices as recording speed, time and the VIN, with GPS on some devices used only for research and development, so the exact data set varies by device and program. Read the terms for the device you are mailed.
What a device cannot see matters as much. It has no way to know whether you are holding a phone, so it cannot score phone use at all. Progressive's Snapshot page says phone use is considered only in some states and only if you use the mobile app, and that the plug-in device is used when the app is not available in your state. The same page says the device beeps for each hard brake, which is a coaching feature you do not get from an app that scores silently.
Practical rules that surprise people
- It must stay plugged in. Progressive's terms say you agree to keep the device plugged in while driving unless it says data collection is complete. If disconnections leave too little data, or the recorded driving is not typical, renewal pricing based on the data may not apply, any participation discount may be removed, and some states add a surcharge.
- You may have to send it back. The device must be returned in good working condition after monitoring ends or you leave. Failing to do so on time could bring a charge of up to $30.
- Monitoring has no fixed end. Progressive's terms say monitoring continues until it notifies you that collection is complete, and that New York requires at least 120 days.
- It records whoever drives the car. A teenager, a spouse or a valet is scored against the policy. That is the plug-in's accuracy weakness, and it is also why some households find it fairer than an app, which can score only the person who carries the phone.
Mileage-based programs lean on the same hardware, because the pay-per-mile insurance model depends on a trustworthy mileage count more than on behavior scores.
Phone apps: the default, with a battery and permissions bill
Most large programs are now app-based. A phone has the sensors, and an insurer avoids shipping hardware. Liberty Mutual says RightTrack needs a smartphone with GPS, an accelerometer, a gyroscope and proximity sensors, and that some Android phones lack them. Allstate and State Farm describe similar app-based collection.
What the app needs to work
Apps run in the background, so the phone's settings can quietly turn them off. Allstate's Drivewise help page is explicit: location settings must be enabled so trips can be detected, the phone needs cellular service and at least 5 percent battery, and it spells out the battery-optimization steps for Samsung and Pixel phones. It also advises not deleting and reinstalling the app, because some trips may not have uploaded. Liberty Mutual says it uses about the same battery as other navigation apps, uploads about 500 to 600 KB per hour of driving, and stops collecting data when the battery is at 20 percent or below to save power. Data charges, it notes, are the phone owner's.
The practical lesson is that missing trips are a common failure. A phone with aggressive battery saving, no cellular service on a rural road or a permission set to "while using" instead of "always" can create gaps. Programs that require a minimum number of trips, such as Allstate's 50, can then withhold full credit even if you drove carefully.
The passenger problem
The app follows the phone, not the car. Allstate says its app can detect when you are a passenger, and updates each trip afterward to include the vehicle type (automobile, train, bus, plane or boat) and, for car trips, whether you were the driver or a passenger. Only driver trips count, and you can correct a mistaken trip in the app. That addresses the most common error, but it still depends on the app's guess.
State Farm uses a hybrid. Its help page describes a small Bluetooth beacon you assign to your car, which starts trip recording on your phone automatically. The beacon has no GPS and cannot track location. When several phones linked to a beacon are in the car, only the first phone to connect records the trip. A listed driver can reclassify a trip, which removes that trip's phone distraction from their score. In practice, if your spouse's phone connects first, the trip is theirs, and the other person's phone does not log it.
That is the trade in miniature. A beacon ties recording to the car, which helps with unplugged phones, but the person whose phone connects first gets the score.
For the scoring side of these errors, see how telematics scores are calculated: braking, speed, phone use; for disputing a wrong trip, see when a driving app scores a trip wrong: how to dispute it.
Built-in car data: no app, and a different consent trail
Many new cars have a modem and report data to the automaker. Some insurers let you share that data instead of installing anything. Nationwide's connected car activation page lists specific Toyota models for SmartRide and SmartMiles connected-car programs, and specific Chrysler, Dodge, Jeep, Ram and Alfa Romeo models for SmartMiles. For Toyota, the page says to add the vehicle in the Toyota app and accept two consents, one for master data and one for the insurance connection. It says you must "enable data sharing for your vehicle data," but it does not list the data types or explain how to revoke consent.
The convenience is real: nothing to charge, install or return. The risks are different from the other two methods.
- You may not know what is flowing. The data goes automaker to insurer, and the data set is defined by the automaker's consent, not the insurer's enrollment page.
- Consent lives in another company's app. For Toyota, Nationwide's page has you accept the consents in the Toyota app, so reviewing or withdrawing them happens there, not with the insurer.
- Regulation is patchy. Montana's telematics chapter, for example, covers agreements between insurer and policyholder and excludes manufacturers and aftermarket suppliers that are not acting as insurers, per Montana Code 33-23-225. State coverage varies; see which states restrict telematics surcharges or data use.
Two public actions show what can go wrong. In January 2026 the Federal Trade Commission finalized an order against General Motors and OnStar. The FTC alleged, in its January 2025 announcement, that GM collected and sold precise geolocation and driving behavior data, including hard braking, nighttime driving and speeding, through its Smart Driver feature without clear disclosure or consent, and that consumer reporting agencies used it in reports insurers relied on. The order bars GM from sharing such data with consumer reporting agencies for five years and requires affirmative express consent for connected-vehicle data for 20 years, per the FTC. The order applies to GM only. Separately, a proposed class action filed in Texas in April 2025 alleges that Toyota and a data aggregator shared vehicle data with Progressive's Snapshot program, and that a plaintiff who opted out of Snapshot during sign-up found Progressive already had his data, per Insurance Journal. Those are allegations, and Progressive did not respond to requests for comment in that report.
Check your car's connected-services settings whatever method you choose; connected-car data, data brokers and your premium explains how that data reaches insurers.
Switching cars, phones or insurers mid-program
Changes are where the method bites.
| Change | Plug-in device | Phone app | Beacon plus phone | Built-in data |
|---|---|---|---|---|
| New car | Move the device or request one for the new car | Usually carries over; Liberty says the score applies to new vehicles | State Farm: a beacon may ship automatically or be requested in the app | New consent and a new data feed |
| New phone | Not affected | Set up again; Allstate keeps previous trips visible | Download, log in, grant permissions; no new beacon | Not affected |
| Selling the car | Return the device | Not affected | Remove the beacon | Remove your account from the car |
State Farm's help page says a new car may need a beacon requested in the app, and there may be a delay before the car appears. Allstate says switching phones means setting up Drivewise again, and Liberty Mutual says your driving score is applied to vehicles you add or replace. If you change insurers, none of these scores follow you; the new company starts its own monitoring or asks for its own consent.
Privacy and the risk of a false score
Each method has a different privacy profile.
A phone app sits on a device that holds your contacts, messages and location history. The insurer's app asks for a narrow set of permissions, but the phone's operating system can show you what it has. Liberty Mutual says it will not sell RightTrack data and may use it for premium adjustment, claims, underwriting and research, and that it may retain it indefinitely subject to state requirements. State Farm says it does not sell your information and may share it with third parties in limited situations. In January 2025 the Texas attorney general sued Allstate and its subsidiary Arity, alleging they collected driving and location data on more than 45 million people through software embedded in third-party apps, according to Insurance Business. Allstate denied the allegations. The case is a reminder to review every app's location permission, not only the insurer's.
A plug-in device is narrower: it sees the car, not you. But it can include location, and it records whoever drives.
Built-in data is the broadest pipeline and the one with the least visible consent trail.
The false-score risk follows from this. A device scores the wrong driver; an app scores the wrong trip; a beacon scores the first phone that connects; connected-car data scores whatever the automaker passes along. Each is fixable, if you can see the data. That is the argument for choosing a method that shows you trips and lets you correct them. For security issues specific to dongles and apps, see Security and privacy risks of OBD dongles and driving apps, and for what happens if the data is requested after a crash, see event data recorders: what your car records and who can access it.
Four invented scenarios
These are hypothetical, to show how the trade-offs sort.
- Maya shares one car with her husband and a teenager. An app scores only the person carrying the phone, and the teenager's phone may not be enrolled. A plug-in device scores everyone who drives. If the household has one safe driver and two risky ones, the device sees the risk and the app may not.
- Luis commutes by train two days a week and drives the other three. An app has to separate train trips from car trips. Allstate's help page says its app updates trips to show vehicle type; a device never faces that problem.
- Priya has a 2024 car with a built-in modem and dislikes extra apps. A connected-car program may work, but she should review the automaker's consent and the insurer's data list first.
- Sam drives a 2009 car and keeps his phone on low-power mode. A phone app may drop trips; a device that stays plugged in may be more reliable, if his car's port works with it.
Before you choose: a checklist
- List who drives the car and whose phones would be enrolled.
- Ask the insurer which methods it offers in your state; some programs allow only an app.
- Read the data list: is location included, who receives it, how long is it kept?
- Check the permission and battery settings the app requires, and whether your phone can meet them.
- Ask what happens when you change cars or phones.
- For built-in data, ask how to revoke consent, since some pages do not say.
- Ask whether you can view trips and correct a wrong one.
Common questions
Which method gives the most accurate score?
None is automatically best. A device is accurate about the car but blind to phone use and to who is driving. An app is accurate about phone handling but can misattribute trips. Built-in data depends on what the automaker transmits.
Does a device read everything my car does?
Not from the terms reviewed. Progressive lists speed, time, VIN, G-force on some devices and plug/unplug events, and says miles and acceleration are derived from speed and time. A device's specifications vary, so read the one you receive.
Can I run an app without location permission?
Programs describe location access as necessary for trip detection. Allstate says location settings must be enabled so Drivewise can detect trips. Without it, trips may not record.
Is built-in car data safer for privacy?
Not necessarily. It removes the app, but the data starts with the automaker and the consent flows differ. The FTC's GM order shows why that matters.
Key takeaways
- A phone app follows the person, a plug-in device follows the car, and built-in data follows the car's connection to its maker.
- Devices cannot score phone use; apps can record trips you did not drive.
- Battery, permissions and cellular coverage determine whether an app captures enough trips.
- Switching cars or phones can reset setup; confirm the steps first.
- Whatever the method, ask what is collected, who gets it, how long it is kept and how to correct a wrong trip.