Northeastern researchers (with Consumer Reports) present a large-scale measurement of the connected-vehicle ecosystem: 21 late-model cars and 30 companion apps, third-party trackers, disclosure gaps, and why vehicle data sharing needs more transparency.

Your car is a smartphone on wheels. Here's who's listening.

The first large-scale measurement study of the connected-vehicle ecosystem.

A connected car is a vehicle with built-in internet access — Wi-Fi, cellular, GPS — that lets it communicate constantly with its manufacturer and outside companies. Over 75% of vehicles sold globally have this connectity built-in.

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It knows where you drive. It knows who you are. It can share this data and more with insurance companies, advertisers, etc...

Report Summary

Partnering with Consumer Reports, we tested 21 late model vehicles and 30 companion mobile apps to understand the privacy implications of the connected vehicle ecosystem.

01 We find that both vehicles and companion apps contact numerous third-party domains, including advertisers and trackers.
02 19/21 vehicles tested send traffic to at least one third party
03 Seven of 30 apps transmit sensitive identifiers to third-party companies

We go through a lengthy discolure process and provide insight into how manufacturer's perceive this data sharing issue.

Our findings underscore the need for continued measurement and scrutiny of the connected vehicle ecosystem.

Partnership with Consumer Reports

Consumer Reports gave the team access to its purchased fleet of test vehicles — a sample that would have cost over $1.2M to assemble independently.

The Paper

This work is peer reviewed and will be published at IMC '26. Read the paper →

The Research Team

We are a team of privacy, security, and networking-systems researchers at Northeastern University. See the full team →

21 vehicles tested, 19 brands 30 companion mobile apps 19 / 21 vehicles contacted a third party over Wi-Fi 7 / 30 apps sent PII to trackers 5 / 30 apps sent VIN + other PII to trackers

EXPLORE THE PAPER

Jump directly to any section, or scroll to see the whole thing.

Research Questions

What is this paper about, and what were we looking for?

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Methods

An accessible explanation of the experiments we ran.

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Vehicle Dataset

A list of the vehicles we looked at

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What We Found

The main results and what they tell us.

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Manufacturer Responses

How the manufacturers responded to our findings

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What It Means

The bigger picture and key takeaways.

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Research Questions

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Connected Vehicle Ecosystem

This diagram shows the data flows to and from a vehicle and its companion mobile app. Both devices send data, including private consumer data, to different 1st and 3rd party servers using Wi-Fi and cellular service. Solid arrows represent flows that were intercepted through our experiments.

The Problem

Once the data gets sent to these servers, it is up to the companies that receive the consumer information to make decisions on what they do with it. Unfortunately, in many cases, this includes sharing or selling consumer data to other undisclosed 3rd parties.

Consumers have no control over their data once it has left their device

In this paper, we take the first steps to address the limited visibility into the privacy implications of the connected vehicle ecosystem. We identify two vantage points in the ecosystem where we can gain insight into the data that connected vehicles are sharing with both manufacturers and third parties: the vehicles themselves and the mobile apps provided by manufacturers.

We ask the following guiding questions:

01 What personal consumer data do connected vehicles and their companion mobile apps transmit?
02 Who receives that personal consumer data?
03 What is the manufacturer response to these findings?

Methods

We investigated 21 vehicles from the U.S. market in a controlled environment along with 30 companion mobile apps instrumented with on-site vehicles between October 2024 and August 2025. Below is a description of the experiments we ran and our setup.

Vehicle Testing

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Wi-Fi Testing Setup

To collect Wi-Fi traffic from vehicles, we configured a custom access point (AP) on a Raspberry Pi and used tcpdump to log all packets that were sent or received via this AP.

This allowed us to see all the destinations the vehicles were sending data to but not the information within the packets as it was encrypted.

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Stationary Tests

Idle Baseline vehicle on — no activity Active Test perform all possible actions

Driving Test

drive 5–45 mph with acceleration & hard braking

Isolating Cellular Traffic

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One hypothesis we tested was whether blocking a vehicle’s ability to communicate over its cellular network would force more Wi-Fi communication. To block external cellular signals, we drove 11 EVs in the sample into a car-sized Faraday tent providing ≈93 dB of attenuation, blocking their cellular connection entirely. Stationary Idle and Active tests were repeated inside the tent to see whether traffic that normally goes out over cellular rerouted to Wi-Fi instead.

App Testing

In total, we experimented with 30 connected vehicle companion apps that were paired with the vehicles at Consumer Reports’s testing facility.

Device Setup

01 We used a combination of test phones and iOS versions for our
experiments: an iPhone 8/iOS 16.6, an iPhone X/iOS 16.7.11, and an iPhone 13/iOS 18.5.
02 To minimize background traffic, we deleted all
non-essential apps on the test phones and tested apps one-by-one, including deleting each vehicle app and restarting the phone before downloading the next app.
03 We used the iOS native screen recording
feature to record our interactions with each app for later review.
04 To capture and decrypt network traffic from
the companion mobile apps, we used iPhones with custom root certificates connected to mitmproxy.

Process for Testing Each App

01 During app installation and login we accepted all permission requests (e.g., tracking,
location, calendar access, Bluetooth, notifications) that the application requested
02 We had a Consumer Reports employee log into the app using
their existing credentials associated with a vehicle on the lot.
03 Once we were logged-in, we manually exercised
all available functionality, such as looking for nearby charging staions, geolocating the vehicle, viewing vehicle data and service history (e.g., tire pressure), viewing notifications (e.g., “doors are unlocked”), and viewing in-app privacy policies.
04 Some apps allowed
us to perform physical interactions on the vehicle, such as remotely opening the trunk. We performed all such actions and verified that the vehicle completed each request.

Vehicle Dataset

$1.2M+ estimated cost to independently procure this fleet, only possible due to Consumer Reports partnership

Manufacturer Brand Year Model Vehicle Tests

Driving Idle In-Tent Cellular

General Motors (GM) Buick 2024 Envista ✓ ✓ – –

Cadillac 2024 Lyriq ✓ ✓ ✓ – Chevrolet 2024 Blazer ✓ ✓ ✓ –

Stellantis Dodge 2023 Hornet - ✓ – –

Fiat 2024 500e ✓ ✓ ✓ – RAM 2025 1500 Bighorn ✓ ✓ – –

Fisker Fisker 2023 Ocean ✓ ✓ - –

Ford Motor Co. Ford 2022 F150 Lightning ✓ ✓ - –

Ford 2024 Mustang GT Fastback ✓ ✓ – –

Honda Motor Co. Honda 2024 Prologue Touring AWD ✓ ✓ ✓ –

Tata Motors Land Rover 2023 Range Rover Sport ✓ ✓ – –

Toyota Motor Corp. Lexus 2024 NX450H+ PHEV ✓ ✓ – –

Toyota 2023 Corolla Cross ✓ ✓ – – Subaru 2023 Solterra ✓ ✓ ✓ –

Lucid Lucid 2023 Air Touring ✓ ✓ ✓ –

Mercedes-Benz Group AG Mercedes 2023 EQS450 4Matic ✓ ✓ - –

Renault-Nissan-Mitsubishi Alliance Nissan 2023 Ariya Platinum ✓ ✓ ✓ –

Rivian Rivian 2022 R1S ✓ ✓ ✓ –

Tesla Tesla 2024 Cybertruck ✓ ✓ ✓ –

Tesla 2024 Model 3 ✓ ✓ ✓ ✓

Zhejiang Geely Holding Group Volvo 2024 C40 ✓ ✓ ✓ –

While
we tested a wide range of vehicles, we did not cover every manufacturer in the U.S. market. As with all empirical studies, our results should be interpreted as a snapshot in time, and may not generalize to vehicles outside our sample or outside the U.S.

Findings

19 of 21 vehicles contacted at least one third party over Wi-Fi, including known advertising and
tracking domains
7 of 30 companion apps transmitted sensitive identifiers (VINs, emails, phone numbers, precise
location) to third parties associated with advertising and tracking.

Transmiting multiple forms of PII to the same third party allows advertisers to build in-depth profiles on consumers

All apps Only apps with cross-context tracking

App VIN Location Phone Email

Click any company chip for what it received and from which app.

Pairing a companion app roughly doubled a vehicle's exposure to advertising/tracking companies on
average, and in some cases added 20+ new ones.

vehicle-only ATA companies

added by the companion mobile app

Manufacturer Disclosures

The team disclosed these findings to the different manufacturers featured in the study, below is an interactve summary of the different explanations received.

Click any box above for more info.

The ongoing theme of all these responses was shifting the blame to the consumer .

- The current system does not give owners the ability to choose.

Assuming owners can find the particular agreements, if an owner decides they are uncomfortable with the data sharing described within them, they are faced with (arguably) unfair choices:

01 accept the agreements regardless of their concerns

02 stop using their car's connected-vehicle features - which includes remote start, the app, and other very useful features

03 stop using the vehicle entirely

As one notable exception, Honda improved its data
collection practices to prevent sending precise geolocation to a third party associated with user tracking.

Conclusion

We found that vehicles, under a variety of real-world settings,
contact not only a wide range of first parties (i.e., manufacturer domains) and car-specific support parties, but also third parties that are known to provide advertising and tracking services.
Vehicles from the same manufacturer exhibit
different network behaviors - this makes it very difficult and expensive to study these vehicles.
When adding vehicle companion apps
to the analysis, we found that vehicle owners are exposed to even more privacy-sensitive ATA communication—in some cases more than two dozen additional trackers.
Our study revealed a large gap between what vehicle
manufacturers publicly disclosed and how the connected vehicle ecosystem actually shares data over the Internet
Based on the opaque nature of vehicular
systems, we argue that there is a need for better transparency to ensure increased visibility into the entire ecosystem to identify and address corresponding harms.