I can think of an easy way to have the controls accessible no matter what's going on on the touchscreen, but then again that's probably what disqualifies me from being the CEO of a big car company.
Take that idea of buttons and knobs and just replace it with another ipad. Make it revolutionary, put the ipad in the middle of the steering wheel, boom.
What about several mini ipads, each dedicated to a single function? We could use OLED displays and pre-burn-in their function at the factory as a label, and leave the display off, except for maybe a single LED, to save power. We could also add some sort of haptic feedback on user interaction with each mini ipad...
make the steering wheel an ipad and swipe to turn!
You could really future-proof the car if you replace the windshield with an ipad. then you can overlay ads on reality just like they do in soccer games.
