Gear stuck in drive
 

I have a 3 series M Sport. I accidentally drove over a large stone which dragged quite badly under the car. After that the car is stuck in Drive. It drove perfectly from the scene of the accident to my home, but once I switched off, I can't start it or get the key out. Any suggestions on what is causing the gear to be stuck in drive?

Sounds like that rock dented, bent or in some way jammed the life out of you shift linkage, you'll need to get it up in the air and do some looking