Having repaired some of the knobs on my dash, I assure you, they are less expensive than a TV. The AC knob is like 2 pieces of plastic and some bike brake style tension cables that hook to a leuvre somewhere inside. A touch screen is going to be a tabled screen and a motor on that leuvre etc.

Granted, I have a cheap little car.

I remember years ago seeing a video about a company that was supposably developing tactile touchscreens. There was a layer underneath the LCD layer that could be puffed out with some kind of fluid to form bumps where the buttons were shown. Nothing has come of this, unsurprisingly.