One of the big problems in design these days (in all manners of design, including UI's in cars) is that the average consumer has no idea that things like this are a bad idea. They don't think about how tactile feedback, or how much they'll have to take their eyes off the road, or auditory input with visual output, or any manner of things that people like us (/.'s) think of. They think that touch is high tech, and therefore better (regardless of the implementation), they put form over function, they want the newest and flashiest, even if it isn't the best. Good design takes a back seat to "cool" design more often than not, because the mass public only wants what's new, shiny and cool. Every now and then, good design and cool design intersect and everybody wins, but it's rare.