I hope devs can take a good look at the 'feature' where impacts often result in the car being attached to whatever it hit. it does happen occasionally in real impacts, but it happens far too often in Beam. it's particularly bad when hitting another car. This would be very bad if racing or derby mode is made available.
Check out the Dev Blog up top from time to time. They posted this a while back . The bridge in this video is a vehicle, and collision is even further improved since this http://www.beamng.com/entries/94-Working-on-friction-and-collision
The problem I believe is with one-sided coltris sticking together. (Don't quote me on that. I might be completely incorrect). Like Dummiesman said above, the devs have been improving collision and so far it looks like they have made a lot of progress on it. Next update should help alleviate that problem.
This is basically fixed in the next update, the collision has improved by at least ten times. Clipping doesn't really happen now, so when the car gets stuck, it's more like what you'd get in real life.