I purchased my 1999 - 323i two years ago at auction for 6000.00. I thought "what's wrong with this car" after I purchased it because the car seemed in great shape. I found this website about six months ago and saw the class action lawsuit posts so I decided to get mine checked out last month. Low and behold the subframe had some major damage and the service manager asked me why I didn't bring it in much earlier (couldn't I tell the handling was poorer?).
I got the car back two weeks ago, the handling is amazing (guess that's why he asked the question). In my case there was a major difference in the ride and handling of the car. I had no reference as to how should handle when I first got it but now I see.
I think that the car was at auction because the original owner probably found out out that the subframe was damaged and he auctioned it off "as is." I just wanted to mention to others out there that purchased their E46 used, you should have it checked out even if you "think" it's ok, you need to "know" it's ok. JMHO