The only V8 S4 is loved for its naturally-aspirated soundtrack and Q-car looks — the ultimate sleeper, especially as a 6-speed manual Avant (the 'longroof'), which commands an 'Avant tax.' Values reward clean, sorted cars with the chain service done; chain-needy cars trade at a discount.
A characterful V8 sleeper — manual Avant is the unicorn
Audi S4 (B6/B7) · value-and-market