I went to leave work. upon turning the car on i noticed 3 warnings appear which required me to read them and acknowledge them. they were all related to the auto braking/pedestrian warning system. driving home the vehicle was driving strange. i noticed that the steering wheel was turned slightly counterclockwise versus normal when driving straight. the car was responding strange when the drivers side hit a dip or rise in the road. the rear end felt "looser" than normal. when i got home i parked it and called the local bmw dealer. they arranged for a tow. once the car got there they put it up on a lift, they called and informed me that the left rear "control arm" (caster link) was broken into 2 pieces. the car was bmw inspected and certified pre-owned, with only 9k miles and a clean carfax. there are no signs of any damage or of anything ever touching the caster link. original wheels, original tires.