These guys have the filter kit: http://erikssonindustries.com/ZF_items/4HP24A/4hp24a.htm Contact info at bottom of the page.. ZF made the 4HP24 in a couple different flavors the "A" is Audi specific read as "Audi" or "AWD" whichever you choose; the only correct one is specifically for the 4HP24A. -Scott