You imply that this is obviously a bad idea, but why? I wouldn't eliminate the idea out of hand. If cars were slightly less comfortable, maybe people would drive slightly less and walk/bike slightly more. Maybe removing temptation by having a phone that doesn't make it as easy to play games is simply a healthier choice.

As a parallel, the Amish are a societal group that isn't being overwhelmed by technology. Contrary to popular belief, the Amish don't shun technology, rather they develop rules as a community to try to figure out how to take advantage of the benefits of technology while avoiding the downsides.

In most Amish communities, the current rule is that using telephones is fine, but they are not allowed to be in the house. They tried it when they first came out, and decided it wasn't working. The current approach is to put community phones in outside sheds so they aren't too tempting, but can be used when needed: http://amishamerica.com/got-a-quarter/

Unfortunately Apple has decided that's the only car they're going to make.