Could be plenty of things - knackered steering bushes, wheel balance (as mentioned earlier) etc. etc. I'll have a look through my BMW service/repair disks when I get home but without actually getting her on a ramp it'll be difficult to help him.
PS do they sell mufflers fot $1000 over there??? - I hope they're made of diamond encrusted gold.
PPS I hope he's going to take english at college.