My car is too old for Android Auto. Here's how I used a spare phone to add it anyway

Working from home has its perks, the biggest being avoiding a hectic morning commute. That means that my car spends most of the week sitting in the driveway. I mostly just use it for the occasional weekend road trip, so I’ve never been able to justify upgrading my vehicle to a newer model with Android Auto support. Ironically, those road trips are where I miss having Android Auto support the most.

For years, I’ve gotten around that limitation by mounting my phone on the dashboard and keeping Google Maps open. This solution obviously works, but it’s far from ideal. Buttons are small, switching between apps is awkward, and, for the most part, it’s flat-out dangerous when driving at expressway speeds.

Android Auto fixes much of this with a simple interface designed for use behind the wheel. I wanted that experience without replacing my car. It turns out I could build it using hardware I already had.

Turn your old phone into a head unit

The trick is an open-source project called Open Headunit. This open-source app triggers your phone’s built-in Android Auto functionality to make it work as an Android Auto head unit instead of projecting to your car’s infotainment system.

Getting started with the app is simple enough, as it is available on the Play Store, but you’ll have to pay a few dollars for it. Unlike many other open-source solutions, you don’t have to go around digging through GitHub repositories and installing APKs. That said, the app is free over on GitHub if you want to give it a whirl before paying for it.

Once the app is installed, you can adjust the display settings to suit the phone you’re using. Open Headunit gives you control over things like resolution and DPI scaling, which is useful if you’re using an older device with a smaller screen, or if you want to increase the size of icons and touchpoints.

I’ve also enabled full-screen mode. This removes the regular Android interface and makes the phone feel much more like a dedicated car display.

Once done, the app gives you a few ways to use the Android Auto functionality. My preferred method is Self-Mode. It is this mode that triggers Android Auto directly on the same Android phone running the app. Honestly, it’s as simple as that. Instead of buying an aftermarket head unit or trying to modify my car’s existing stereo, or even plugging into another phone, I can just launch the Open Headunit app, tap the Self Mode button, and watch Android Auto come to life on my phone’s display. And that’s precisely what I’ve done.

Moreover, there’s no missing functionality here. Android Auto provides a driving-friendly interface, while you get access to navigation, music controls, Google Assistant, and other Android Auto features without needing the car itself to support the platform. The entire experience is surprisingly stable and seamless.

You can use another phone as a receiver, too

That said, Open Headunit isn’t just limited to Self-Mode. If you have a spare Android phone or tablet, you can also use it as a traditional Android Auto receiver.

In this setup, your primary phone remains the device running Android Auto. Open Headunit runs on the second device and displays the Android Auto interface there using a wireless helper app or a USB cable.

This is useful if you have an old tablet with a larger screen. Rather than dedicating your main phone to the car, you can leave the tablet mounted on the dashboard and use your regular phone as the source. This is also where things get a bit more complicated. Helper mode’s functionality is a bit hit or miss when using newer versions of Android Auto.

I’ve had limited success with connecting to another Android device using wireless helper mode. On the flip side, connecting the devices using a USB cable has worked reasonably well to the point that it would be my go-to suggestion if that’s the route you want to take. It’s essentially the same concept as an aftermarket Android Auto display, except you’re reusing hardware you already own.

For me, though, the built-in Android Auto functionality is what I tend to use, as it means I don’t need to keep another piece of hardware handy.

Just grab yourself a sturdy dashboard mount or adjustable phone clamp, and a high-quality car charger, as keeping the screen on continuously with Android Auto running is bound to put a dent in battery life, and you’re good to go.

A surprisingly good upgrade for an old car

Honestly, I wasn’t expecting the app to work as well as it does. A few minutes of setup, and I’ve been able to turn my phone into an honest-to-goodness Android Auto head unit while saving myself hundreds of dollars, or even a much more expensive vehicle upgrade.

Instead of bothering with juggling apps on a smartphone display, I now get the real-deal Android Auto layout complete with touch-friendly controls, navigation, and music, all designed around the driving experience.

While the receiver functionality is useful if you want to turn a spare smartphone or tablet into an Android Auto receiver, the ability to trigger my phone’s built-in Android Auto function proves to be the real killer feature.

It isn’t quite as seamless as having Android Auto built into the dashboard. You’ll still need to mount the phone, keep it charged, and spend a little time getting the software configured. But that’s a small price to pay for the massive upgrade in convenience that you get.