Here is some stuff at ars about infotainment distractions:
I concur that Siri is unusably distracting while driving. I attempted to get it to give me directions to T.'s school in [ETA: the Town of] Harvard last [ETA: school] year and nearly ran off the road. I resorted to programming the aftermarket nav system in the car instead (Pioneer, IIRC).
The i3 nav and so forth system tends to do what I expect it to do, which is nice, and I don't have any problems with input. Wow, I sure hated the way the touch screen on the Pioneer interpreted attempts to press buttons on screen. Absolutely road rage provoking. The i3 does not have a touch screen and I am A O Good with that, because the wheel thing works Just Fine.
This post brought to you in part by Duvel Trippel, so if it's not completely coherent, well, blame me for tipsy-posting.