Spares for the s4 are in the same bracket as an audi v8 rare and expensive. The A8 is another story. There have been far more of these cars built so the spare part prices are a lot cheaper also may of the parts in an A 8 were also built into an a4 and a6 so used parts and aftermarket parts are generally cheaper and more available. The demand for A8 parts are very few at our scrapyard so i can only imagine that there is not mutch that goes wrong with them. The axel outriggers are made of alluminium and are very prone to wear but that is about the only thing that is regularly asked for
