Too late, you get literally all of that on current Teslas for free (well, Steam games cost money I guess). I actually can't tell if grandparent was being sarcastic or not, but yes: these are already products.
I was indeed being genuine with my question, as I see these hacks (Mazda headunit too) but I’m curious if I’m missing the point other than the sake of tinkering.
Don't complain when they extrapolate to the subscription based door locks and braking system. Just about everyone would almost have to sign up for them! /s