There are a few places to check out online if you are looking for a particular Audi part. Looking online first can often save you money. There are several forums that are all about Audi topics. These forums are great opportunities to do some research and network. This option is especially great for older models. You can see if any other member has what you are looking for, and in the case that they do not you will likely be able to get some free advice.
Use auto directories! Search for “used car parts directories” and you will find several of them. Some resources also have an auto parts “search engine.” Searching efficiently will help you find the part you need.
If you cannot find the part online, contact your local Audi dealership.