You can add "OK Google" or "Hey Google" to your car stereo with VLine VL2 system, even if you are not using Android Auto. "OK Google" or "Hey Google" voice assistant commands can work on VLine stand-alone, if you enable it. Read here how you can enable Google voice assistance in your vehicle with vLine:
https://gromaudio.com/blog/2021/11/h...id-car-system/
https://gromaudio.com/blog/2021/11/h...id-car-system/