Moulding in sideskirts opinions needed

[fowljesse]

I have sideskirts that don't fit well, so they need help. What are the best ways to fill gaps.. And are there easyish ways that are good?
The deal is; there is almost an inch between the sideskirt (MazdaSpeed CorkSport), and the side of my car, where the previous owner cut it.
What I'm thinking about doing is: glueing it on with "GreatStuff" expanding foam, and shaving the foam smooth, to Mould it, then Bondo, Primer, and paint. Would this work? Is there a better way? I'm going to be making other aero mods, and need to do this on those, too.
Thanks.

[93_4Banger]

try to leave the bondo to a minimum because it cracks very easy if it built up to much, i would suggest a product called marine-tech and an adhesive called tiger seal, it did wonders on my skirts and have yet to see any cracks and they've been flexed to there limits thats forsure.

[fowljesse]

Thanks. I'll look for it at the boat store.