Car mufflers and truck mufflers are often different. Many cars, but not all, have mufflers that are right at the tail of the exhaust system. For these, the muffler tip is a part of the actual muffler. When shopping through our Audi S4 muffler selection, keep that in mind, as most mufflers are actually listed as universal mufflers. Some of the most popular mufflers are Flowmaster mufflers and Magnaflow mufflers. If you have any questions about mufflers for your Audi S4, or if you are having trouble finding an Audi S4 muffler on our website, please contact us.