OK...so now i have dubious aftermarket roof spoiler. Why is it that all the A3's i look at in the car park etc, have a roof spoiler that fits flush with the roof line....yet when i asked here how it fits people said its bonded on. the small lip on my tailgate is already flush with the roof so anything i stick on it will be proud of the roof line. The spoiler i have fits quite well where it should but the leading edge is about 10mm thick so naturally it sits 10mm high... am i missing something here ??