Hi my Audi Concert cd player started acting up yesterday, was playing away fine for about 15 mins then noticed it skip a little then froze at the start of the next track and cd wouldn't eject. Switched off and back on and ejected the cd. Tried a different cd and got half way through the first track and same again, this time it displayed CD ERROR on the display and SERVICE. Any advice on what to do? I have a warranty which would probably cover costs of repair or replacement but I'm thinking how could I swing an upgrade with part of the costs covered by the warranty repair?