The other day I test drove a Volt. The exterior is nice, the interior is nice. The only thing I really disliked was the center control panel because of the capacitive touch sensor 'buttons'. To me this makes no sense in a car. The whole point of this technology is for use in things like touch screens and smart phones where the display changes. With these interfaces, the action resulting from touching a particular spot on the sensor depends on the state of the display at the time. In this case you are viewing the display and can easily determine the state and thus you have a good idea what the 'touch' is going to do (launch an application, open the keyboard, type a letter etc.)
In a traditional car, when your hand gets to the correct control, you just apply a little more pressure in the appropriate manner (push, twist, slide) to activate the control you want. In the Volt, if you 'miss', you have probably activated something you did not intend. Now you may have to deactivate whatever it is you messed up and find the right control to do what you want. If you try to do this by touch, you may inadvertently make more incorrect choices. Most likely you will have to take your eyes off the road to find and touch the correct control. This is an obvious safety concern. It is like trying to dial your phone while driving, it can be done but it is generally not a good idea (and illegal in some places?).
On touch screens, a touch sensor makes economical sense too because instead of having a bunch of different controls which might not cover every situation, you can have a single 'all-in-one' control that can be reconfigured on the fly. Again, this works because you can see the display before you make your decision. In the Volt, there are a set number of controls anyway and their positions never change. So why use this technology? It isn't necessary. It would be much simpler to just have buttons with actual tactile feedback so that you do not accidentally tap the wrong thing. What is the advantage? Weight reduction? Cost reduction? I can't imagine that a set of 'regular' controls would add more than a half a pound and/or a few dollars and probably would have saved on the R&D. It seems to be a solution for problem that does not exist (although it is probably easier to clean, I'll give it that).
Volt engineers: You did a great job with styling, aerodynamics, power management, requirements (I think the 40 mile electric range was a good compromise) and a bunch of other stuff, but I really question the thinking on this interface, please reconsider for future models.