After disconnecting the battery RNS-E unit is asking for a pin to be entered:- This is the first time its done this even though I've disconnected the battery a number of times in the past as well as completely removing the unit. After reading this thread :- http://www.audi-sport.net/xf/threads/a4-rnse-radio-code.233307/#post-2332883 I guess I will need to pay for a new pin number. I phoned the dealers and they quoted £45 to connect the car up to their diagnostic equipment and download a pin from Audi Germany. The eBay link is a better option at only £6.99. Does this pin request on a fix number of times when the power is lost to the unit or is it random number and I was just lucky it hasn't happened before? I don't want to have to pay to get a my radio working every time I disconnect the battery.