YOUR OLD CAR CAN DRIVE ITSELF — A 999 DOLLARS OPEN-SOURCE BOX ADDS AUTOPILOT
A camera box on your windshield and one cable plug gives your old Honda or Toyota adaptive cruise control, lane centering, and automatic braking with traffic.
by comma.ai
AutomationAI
- difficulty
- ●●●○○
- time
- an afternoon
- license
- MIT
- repo
- repo ACTIVE63,278 stars
●●●○○ · an afternoon · MIT · 63,278 stars · repo ACTIVE
WHAT YOU’LL NEED
- Dev board / microcontroller — runs the project firmware
Partner
COMPAREE VERDICT
openpilot is the most mature open-source Advanced Driver Assistance System (ADAS) in the world, with 63,300 stars and a decade of real-world data behind it. It adds adaptive cruise control, lane centering, and automatic braking to cars that never shipped with those features — including used Toyotas, Hondas, Hyundais, and over 300 other models. The catch: you must buy the comma 3X hardware box from comma.ai for 999 dollars (currently; prices have changed in the past), and your specific car must be on the supported list. Not all cars get the same level of support — some receive full longitudinal control (gas and brake), others only lateral (steering). The installation is reversible and takes an afternoon, but the first week of calibration and learning to trust the system will feel longer than the install. The single biggest risk is overconfidence — openpilot is not self-driving, and you must keep your hands near the wheel and eyes on the road. If you treat it like Tesla Autopilot (which it resembles), it works beautifully. If you expect Waymo, you will be disappointed and possibly unsafe. For someone with a compatible car who drives highway miles regularly, this is transformative. For someone whose car is not on the list, it is a weekend spent researching alternatives.
IN THE REPO
NOT IN THE REPO
- —MIT license — unrestricted use, commercial or personal.
- —The repository contains the openpilot software stack; the comma 3X hardware must be purchased from comma.ai.
- —Over 300 car models supported, but support quality varies — some cars get full longitudinal control, others only steering.
- —The car compatibility list lives in a separate repository (openpilot/car_info) and changes with each release.
- —Installation requires a one-time harness plug behind the rearview mirror; no permanent modification to the car.
- —You are legally and physically responsible for the car at all times — openpilot is classified as a driver assistance system, not autonomous driving.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
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Videos
A drive to Taco Bell
No official installation video provided in the payload; the community has produced walkthroughs on YouTube, but no specific URL was given.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Check if your car is supported(The compatibility list is in the openpilot/car_info repository. Some cars are fully supported, others only partially. If your car is not listed, stop here.)
- 2.Order the comma 3X and correct harness(Available from comma.ai. The harness is model-specific; double-check compatibility before ordering.)
- 3.Follow the installation guide for your car(Guides are community-maintained and vary by model. Expect to remove interior trim and route cables behind the dashboard.)
- 4.Complete the calibration drive(After install, openpilot requires a calibration drive on a straight road to align the camera. This takes 10-20 minutes.)
- 5.Spend a week learning the system's limits(Do not trust it immediately. Learn where it excels (highway lanes, steady traffic) and where it struggles (unmarked roads, complex intersections, heavy rain).)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- Buying the hardware before confirming your car is supported — the compatibility list is strict, and partial support means you might only get steering or only get cruise control, not both.
- Assuming openpilot is self-driving — it is not, and treating it that way will put you in danger. You must stay attentive.
- Installing on a car with factory ADAS already enabled — some cars require you to disable or override factory systems, which may void warranties or trigger service warnings.
- Skipping the calibration drive or rushing it — a poorly calibrated system will ping-pong in the lane or disengage constantly.
- Not reading the model-specific notes — some cars have known quirks (e.g., Hyundai/Kia models may require a specific firmware version, Honda Sensing cars may need additional configuration).
- Overconfidence after the first successful drive — the system will eventually encounter a situation it cannot handle. You must be ready to take over immediately.
Is this legal?
In most jurisdictions, yes — openpilot is classified as a driver assistance system, and the driver remains fully responsible. However, some regions (notably the EU and parts of California) have restrictions on aftermarket ADAS. Check local laws before installing.
Does this void my car's warranty?
Possibly. The installation is reversible and leaves no permanent marks, but some dealers may refuse warranty claims if they discover aftermarket modifications. comma.ai does not provide warranty coverage for your car.
Can I use openpilot on a car without factory cruise control?
Usually no. Openpilot requires the car to have at least basic cruise control hardware (throttle-by-wire, electronic brake assist) to function. Check the compatibility list for your exact model.
What happens if I take my hands off the wheel?
The comma 3X has a driver monitoring camera. If you look away for more than a few seconds or remove your hands for too long, it will beep, then disengage. Repeated violations may lock you out temporarily.
Can I run openpilot without buying the comma 3X?
Technically yes — the software is open-source and people have built DIY rigs using off-the-shelf cameras and compute modules. Practically, no — the comma 3X is engineered for automotive environments (temperature, vibration, power stability) and DIY setups are fragile and potentially unsafe.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
Over 300 car models are supported, but the experience varies — some get full control, others only steering. If you have tried openpilot, which car did you install it on, and did it meet your expectations?
comma.ai
Founded by George Hotz in 2015 after he built a working self-driving system in his garage, comma.ai has spent a decade refining openpilot with data from thousands of users driving millions of miles. The company sells the hardware and maintains the software as an open-source project, funded by device sales rather than subscriptions.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM23d ago
Practical notes from our verification: openpilot has 63,300 GitHub stars and the MIT license is unrestricted, but the $999 comma 3X hardware is not optional — DIY rigs exist but are not recommended for safety-critical use. The repository is actively maintained, with the last commit within days of this check. The car compatibility list is extensive but nuanced: some models (e.g., newer Toyotas with TSS 2.0) get full longitudinal and lateral control, while others (e.g., older Hondas) may only support steering. The biggest surprise is not the technology — it works — but the responsibility: you are legally and physically in control of the car at all times, and the system will hand control back to you with little warning if it encounters something unexpected. The afternoon you spend installing it is trivial compared to the week you will spend learning to trust it appropriately.