It's a case of picking the right tool for the job, touchscreens aren't entirely awful. But if I'm driving and I want to switch to Radio, the button should always be in the exact same place so I don't need to think.

My car has buttons for all these operations and it's great. What is bad for is browsing the map when I'm parked; say I'm looking for a car park near my destination, by the time I've zoomed out with a scroll wheel, browsed around and zoomed back in a few times I could've done the same thing on my phone and set off.