Hi, Im new here, just recently bought a 58 plate S3. Pretty decent motor, had went to hopefully get an 07 plate RS4 but the Audi dealership had just sold it. Wanted something quattro and only other car that stood out for my price range was the S3. Anyway, i have the standard audi concert with Bose set up. How easy is it to remove the head unit and install a Navigation system that ive seen in newer models of the S3 and RS4s etc? Thanks.