If your car has the OEM sat radio module you will have to upgrade it to one of the newer modules as the RNS-E requires newer software. The old module will stay locked on whatever station it was on when the old radio head is pulled. There are a lot of NIB old modules on sale out there right now but they don't work with the RNS-E. The modules are the same ones for the A4/S4/A6/S6/RS6 so they are common but later ones are not cheap unless you find one on Ebay.