SmithCommaMichael

I got the MB Quart adaptor at a local audio shop (which dropped its MB Quart Account but happened to have one of these left over) for $30. I used JBL GTO series 5.25 components in the front door (the stock setup in there, with bose anyway, is a 4" component with a 1" tweeter near the door pull). I did a JBL GTO 6.75 3-way in the rear deck. Crutchfield had great pricing on these last month...not sure if they still do. They sound WAY better than the stock 8 year old paper bose speakers. I don't think a component is necessary in the rear deck. I definitely still feel the need to put a subwoofer in the trunk as well, but its not in the budget now. Once you have had a sub, you will never be happy without one. But, to answer the question... DEFINITELY get the adaptors. 4" speakers can't provide the depth of sound that you need in that location.

S4andTLS

MB Quart speaker kits-just got some here-U.K.-http://www.nexxia.co.uk/Framepages/audi2frame.htm~~~~~

S4andTLS

Actually-the kit below is for any brand-I went to 5 1/4 up front-stock was 4"