Had mine close to 5 years now, fantastic cars and having driven an S5 I found no noticeable difference in the drive or performance, so for me a good S1 seems like rather a bargain!
All sorts to watch out for but once fettled and as long as they are stored in a dry garage they are pretty reliable.
Make sure it has a good history, look at a few if you can, and read read read all the old threads in the Aero section, loads of info especially if you go back to the oldest threads via the search function (around 2006) as the cars were quite new then and there was a lot more information being posted.
