TBH I don’t remember if it was wired or wireless but my understanding is that GrapheneOS’s implementation is essentially the same as what is included on stock android for Pixels, so both wired and wireless work (https://grapheneos.org/usage#android-auto).
I used it with a stock system so not aftermarket. Do you have any specific reason to believe aftermarket systems wouldn’t work? If they support android auto you should be fine.
was it with wireless android auto and with after-market receivers like jvc?
TBH I don’t remember if it was wired or wireless but my understanding is that GrapheneOS’s implementation is essentially the same as what is included on stock android for Pixels, so both wired and wireless work (https://grapheneos.org/usage#android-auto).
I used it with a stock system so not aftermarket. Do you have any specific reason to believe aftermarket systems wouldn’t work? If they support android auto you should be fine.