Note, "something like."
No, I wouldn't want an

TV in my car. I'd love a Mac or even a glorified iPhone (or rumored Mac Tablet), possibly with a custom UI and version of OS X and Front Row, in my car. Touch screen, AM/FM radio, CD/DVD (Blu-Ray/HD?), WiFi syncing to my home network when in range, GPS with Google Earth, maybe even 3G, since it would all be powered by the car. Maybe a battery for when the car is off.
A standard installable car stereo form factor with a mechanized slide out screen would be nice, as that would make it available to people who aren't going to buy a new car. They'd almost have to, to have any significant market effect. Either that, or partner with MANY manufacturers.
Bottom line, a sweet, Apple designed vehicle interface. I'd be willing pay about the same price as a Mac Mini, maybe a little bit more.
Let it be known, I think this is UNLIKELY (anytime soon), but I can still dream. So don't hate. After all, better interface integration is the future, and I've experienced few interfaces that rival Apple's design.