IMO it shouldn't be a touchscreen at all. By nature you have to look at it to interact. Just have a nontouch screen for display purposes, and physical buttons to interact with it as necessary.
Yet the car comes with a device I also need to take my eyes off the road and poke around at.
It's illegal to use your cellphone while driving in many areas --- so they built a cellphone UI into the car --- which is every bit as distracting and dangerous to use while driving.