My 99 A3TS is now on it's second concert HU after the first one got the all-too-common dodgy volume knob. Now it seems that the replacement is going the same way! I've just been reading this http://www.erta.ru/review/chorus-problem_eng.shtml and I'd guess it's the EEPROM failure, not the simple tightening of the screw, though would love to know if this has worked for anyone as a simple repair? Either that or to ebay for a replacement....the replacement HU was slightly wider so had to make a small cut into the dash, which has worked for 3 ish years. Will the slightly newer Concert (2?) HU with CD player out of a newer A3 work in my 99 A3 without any drama or is nothing that simple!? I've got a Sony CD Changer into my Concert HU as well - it would be great if this would work with a newer Concert CD HU as well. Thanks in advance.