Re: Touch screens
The MOST useful feature of in in-car navigation systems is being able to see where the hell you are WHEN YOU CAN'T GET A PHONE SIGNAL. I bought a 4WD Toyota specifically because of the nav system with CD-ROM based maps. When you're roaming steep dirt mountain roads, you rarely have a phone signal and GPS isn't all that easy to lock onto either. The inertial navigation backs up the GPS and I can at least find my way back.
On my motorcycle, I use one so I don't have to squint at street signs and look for street numbers on buildings. I can pay attention to my driving and avoiding all the 4-wheel drivers trying to kill me.