First post here as I just purchased a 1995 S6. I have searched the forum but could not find any conclusive answers. My 1995 S6 sedan came with an Alpine head unit and the rear shelf speakers removed. The original Bose grills are still there. I tried to fit in 6x9 speakers in existing holes but they were a bit too large and the original Bose grills would not fit over the 6x9's. Before I go buy new speakers does anybody know the largest speakers that will fit in the rear shelf that will allow the Bose grill to cover them?...5x7? 6 3/4 round? 4x6? Also, does the rear door accommodate 4" speakers? Any tips on taking the door panel off to access the rear door speakers? Thanks.

The Original S car forum or the C4 platform 100/A6 chassis forum or even the audio forum. The A6 or S6 isn't specifically covered in here.