I have two problems with the touch screen idea. Feel and finding.
I have the Tesla Homelink activated to remotely trigger an opening motor as I approach. The problem is, that as I'm driving I need to use more than one finger to push the Homelink button.
I reach my hand down, rest three fingers, the pinky, ring and middle, on the lower lip of the VDS bezel. That stabaizes my outstretched arm as my index finger goes in to punch the Homelink button. If I don't do that, then the odds are 25 percent that I will hit an ajoining button or a non funtioning area of the screen. If it were a protruding or textured button/switch I could lightly drag my finger across a whole row of buttons braille-style counting them from a known start point and push the one that is the final count or that has had a specific texture-feel added to it.
Worth pointing out that the screen-change arrows are on the corners so I can single-finger-stabilize by setting my finger in the protruding corners of the frame bezel for guiding my finger in pool cue style.
I just can't see how this screen thing will work at minimum without "resting" places designed for other fingers. Of course, this will eat up valuable screen real estate but if you doubt me, try mounting your Iphone at arm's length in your car and try to program it at inconvient times like when turn steering, leaving a stoplight, navigating a bumpy road, pulling into a parking lot. all while talking with someone in the back seat... I guarantee you that you will resort to the OFR "Other Finger Rest" technique.
I hope when they are testing with customers that the have the seating, 17"screen and an interlocked steering wheel mounted to a motion base and a surround video screen simulator to test under real world driving multi tasking foot, arms, distraction, motion conditions.
Maybe an non-GM cheapo version mounts the whole thing plus video cameras to a truck or trailer while it drives around a road course as testers ask the customer to perform a series of tests.
This science has been covered by car makers, aircraft manufactures, military contractors, NASA, Universities, etc, Buttons and switches are not just about layout but have a specific feel to them such that you can find them in a dark an bumpy ride. The flat screen seems on the face of it, counter to that thinking. I have a few ideas that might work so I hope Tesla folks are addressing these issues.