Yeah, I molded my flares to the car, too. Used a multiple step process to do it:
1 - bonded the flares to the fender with a special adhesive bonding agent
2 - riveted the flares in place
3 - cut away the fender overhang inside the flare
4 - created a full lap joint behind/inside the flare between the fender and the flare
5 - used body filler to fill in the rivet divots and the seam line.
The resultant flare is very strong. You can grab and shake the car by the flare without any flexing in the flare. They're now truly part of the body.
Wheeeeeeeee!!!!!!!!!! That's awesome! All that hard work has paid off. I hope they're strong and don't end up cracking like I've seen on so many poorly fit fiberglass body kits. Can either you or Mr. Woolery please explain in more detail how the flares were moulded to the fender and what you did to make it so strong? I get lost at "created a full lap joint behind/inside the flare between the fender and the flare". I know what a lap joint is but I'm still a little confused.