Hi guys. First post, so please treat me gently! I think I've bought all the right kit to fit my Alpine CDA-9855 into my A4; the facia panel, PC5-90 aerial adaptor and PC9-408 harness (I have the fully-amped Bose). I whip out the old Concert II, clip all the connectors together and..... nothing. Your help will be much appreciated! Thanks.