All touchscreens provide zero tactile feedback or spatial info about its setting. Thus to use any touchscreen, you always must take your eyes off the road to look at it. Thus no matter how logical or attractive or fast the display, screens are always less safe than any tactile alternative control that lets you keep your eyes on the road.

Also, for car devices that provide intuitive feedback on their activity (wiper motion, fan noise, air temperature from outlets, audio volume, etc), you don't need a screen to confirm that it has changed.

And since these devices are the ones that I change most often (and music), I'd much prefer to control them on the steering wheel or verbally, and never use a screen.