Recently sold my 2002 B5 S4 and still have the bolt in roll cage that I used to run (on track and street) with Sparco seats and Schroth 5 point harnesses. Looking to get $500 for the roll bar and I also still have the seats with adjustable sliders and harnesses if someone wants the entire package for $2,000.
Also have 2 sets of 17" SSR Comps in great shape, both in need of new rubber (225/45/17). For those who don't know, the wheels are about 17 lbs as compared to 27 lb OEMs which makes a huge difference in rotating weight/acceleration, and the offset gives a better look IMO. $600 per set or $1,000 if take both sets at once.
This stuff would all have to be local pickup in Southwestern CT.
The cage is made by autopower. It is bolt in and I have had it in and out of the car a couple times over the years pre and post kids. It's the race model at the bottom of this application list http://www.autopowerindustries.com/ApplicationList.aspx