That's pretty interesting. I myself actually never considered insuring my cars, or any other RC, until I started flying over the Summer. Yes, TornadoGuy tried flying, though I am not too good at it yet.
Some modelers at the park I go to brought up having insurance, and they even showed me their cards. I think it was AMA, but don't quote me on that. At first I was a little surprised, but they went on to explain it is the real deal. They said it is crucial to have if your in the air, especially when they fly indoors at their local Armory, because planes can be dangerous in a close proximity, especially if a mechanical error occurs such as a rudder, or aileron failure.
I guess it's all personal preference. I do not know of a specific RC car insurance, but I am sure they're out there.
Good luck,
Joe