I own a 2005.5 A4 with the navigation package/MMI.[/auote]
Your 2005.5 A4 doesn't have MMI it has an RNS-E - that's a very important difference.
Usual dealer reply, and 100% wrong. Those versions of the module WILL 100% work in your car, no ifs, no buts, no maybes.the part I seek is 8P0-862-335T or P. I then followed up with Audi USA to verify this and they DID suddenly know about that part... but went on to say that while it is compatible with my make and model... my VIN# is such that it would not work in my car.