I'm terribly sorry to post a new thread on such a simplistic topic, but I'm stuck at square one. I'm in the process, or at least trying to get in the process, of installing a RNS-E (Euro) into a 2004 A4 Cab w/Bose. I've printed the very helpful guides posted by Justin, though my radio removal keys don't seem to be working. No matter how hard I push them, they're not catching. They will all go all the way back against the unit, though when I try to remove the unit, two of the keys just keep coming back out. Is it possible that I have bad keys? Any suggestions...?