I'm interested in buying my friends 2003 Audi A4 Quattro 1.8T 5-Speed perfect condition, 85,000 miles for about $9,000, perfect condition. I've been doing some research, and I'm now extremely nervous about buying it because I'm reading multiple multiple complains about the oiling system. I'm reading that it develops engine sludge extremely easily and ruins the engine. This really scares me and I'm wondering what precautions should be taken to avoid this seemingly almost unavoidable clockwork. I love the car, but I don't want to have an anchor and am now wondering if the engine will last as long as my Ford Tempo with 200,000 miles and great engine. I'm thinking that Seafoaming the oiling, fuel, and vaccuum system every now and then (20, 30k) should help keep the sludge away. Who has any suggestions as on what to do to avoid the catastrophe?