Strange thread. The discussion went from a Buick Lacrosse to some guy stuffing a car seat into a 2 series and snapping photos for the thread.
My wife drives an X3 35i. We won't be at the booster stage for awhile, but I think rear facing seats take up just as much room anyway. It's fairly spacious, comfortable, and it has enough grunt to embarrass ricers and speed ahead of whomever is being a dick on the road. It doesn't handle at all, but you'd have to be a fairly awful person to really put that to the test with kids in the car.
THE IMPORTANT THINGS IN LIFE:
N/A, 8000RPM REDLINE, CLOSE RATIO MANUAL, RWD, LSD
AE86, S2000, E46M3
Scratch that...fat, boost, AWD, DSG