For me, I tried a Pixel 3 and a Oneplus 7 Pro, with two different cables, and the instability issues were the same. So it's not clear to me that the issue is outside of the head unit.

For the first 2 months of me owning my car (it's a 2021 mx5), I had to force close spotify immediately before plugging the phone into the car (It was like a 30 second window) or the car would refuse to output any audio. Without any change to the cable or the car, and with the same handset, the problem suddenly disappeared. The only thing I think of that could have fixed it is an over the air update for my phone.

Either way, it's branded "Android Auto". I'm going to blame Google for anything that doesn't work optimally. If they cared, they could certify their product.

Yup - the common element between my phones is the underlying Android software / Android Auto software.

I misread your previous comment has the problem originating _inside_ the headunit. Just wanted to clear that up since my response probably seemed pretty superfluous.

No, you read it right. I mean - clearly I don't know the origin. My Mazda OEM head unit was slow and unstable out of the box, and continued to be so when I installed Mazda AIO Tweaks (with Android Auto.)

Specifically running Android Auto became more unstable in March 2020, without being the head unit updated. In other words, probably the phone (Android Auto) was updated. Possibly in a way that was backwards compatible with OEM Android Auto, but not the AIO Tweaks version.

That's a long of saying, there's probably multiple potential sources of problems and failure; not clearly the hardware/software of the head unit, and not clearly the Android Auto software. But a bad combination of the two.

But it's all guesswork on my end! When I see others having the same issues with OEM Android Auto, it does make it seem more of a clear Android Auto software issue. (And we haven't really ruled out idiosyncrasies of the handsets and USB cables.)