Yes. Thousands. I have seen the repair bills. (I didn't say they were particularly smart.) That car has had enough new parts that have been thrown at it to make 2 additional 300TEs.

They also have a '96 S320 that they have spent as much or more on various items.

Same situation - car was given to daughter to drive. She is in college. I have some reservations about her driving the car anyway (as if it were mine!). Several months ago she got it hung up on a big metal pole (still don't know how she did it as the pole is over 3 feet tall) on the right rear. Cost a couple more thou. to get it repaired from that.
The dealer is the one they have been taking it to - they have thrown parts at that car from the day they bought it - brand new.

Anyway - I sure would like to know what you find out....