Yea you’re in the right place lol. Like others in this thread, ive also thought about this a lot.

I watched a video recently of someone using a pi for android auto: youtu.be/Puk_pzMGd7c

I think the only problem you’ll find is that the software would need to be more custom if you didn’t want to use Android auto. Some kind of customized launcher for the pi or something akin to that to mimic a infotainment system.

IMO, using a pi for android auto would be the easiest way to do this but totally get wanting to do it on your own.

I think as long as you use something like organic maps and have a GPS module, a pi should be able to at least do GPS. That said, I think you have to use downloaded maps in that case. I can’t say for sure but that’d be my best guess.

As for screens, my advice is just buy a screen from pi. I looked extensively for a screen that you can hook up to a pi with usb c or anything else and from what I saw, a lot of the options for touchscreens are worse and or more expensive than what pi offers at $65 and its about as plug and play as it gets since they built it.

In all I think its very doable hardware wise. Software would maybe be your only hurdle depending on how exactly you want this set up. If you wanna throw a couple weeks of work at it, I’d be interested to see it so def post again if you do.