Yep, I keep wrecking my car on the tiniest piece of garbage lying on the road. Personally, I think it's difficult enough driving the cars without worrying that having a 1 pixel collision with a stop sign or lamp post total the vehicle. The game is really just too small of a visual scale to add this level of collision, imo.
Stutters are back for me too. They were gone in 24.4, but now every 30 seconds or so, the game locks up for half a second to a second.
Fresh world, insane sized hordes. PC, Win 7 Ultimate... I can provide further details if necessary.
Shin