I have a 99 323i auto with 174k just recently I had an issue arise i cant find any info on. This week I was driving and eveything was fine and pulled into the vac. at the car wash and when I decided to leave my car would not go into reverse! Never had an issue before. So I pushed it out of the stall and put it in drive .....all foreward gears are perfectly fine (even does burnouts) well i drove it home about 1 mile away pulled in the driveway and everything is fine again????? went another week fine and did the same thing the other day at sonic? Drove a lil ways and it started working again! When it does go into reverse it doesnt slip or hesitate any I have no idea local shop said something about some kind of sensor possibly? Any other ideas????