Which used Audi A4 sports should I buy?
Go for a model from 2006 or later, if your budget will stretch that far. Chassis modifications made it better to drive, while the 2.0T FSi engine that became available then is the pick of the line-up.
The 1.8 turbo engine that powers the cheapest model is also the most plentiful second-hand, as well as the best choice for keeping ownership costs sensible. There are also 2.0- and 3.0-litre diesels that are good but scarce second-hand, a 3.2 V6 with Audi's quattro all-wheel-drive system and the S4, the range's performance flagship.