I've owned and worked on 5 A8/S8 cars from 1998 to 2001 over the last 3+ years and have fixed many things. Including completely disassembling a '99 down to the bare aluminum chassis. they have a few flaws but over all are very well made.

My cars
1998 A8 Ming Blue and Light grey inside 160,000 miles (sold)
1999 A8 Aluminum Silver and Blue inside 217,000 miles
2001 S8 Black and Black 173,000
2001 A8L silver and black inside 198,000 miles