Got into my A3 8P this morning, turned it on, waited a few seconds for the memory cards to load, they loaded but with no sound? Turned the car off and on again to no avail, radio and cd player have no sound either?! It's the Audi RSN-E system. Anybody experienced this before? Mine has the Bose system so I'm wondering whether its a loose wire? Fuse? Knackered amp? Many thanks in advance.