Front Lip Mounting Question

Apparently this question has gained no merit in the Exterior section of good ol' AF, so I will pose it here.

I've been talkin about making body kit pieces for my car, and have thus far succeeded somewhat in doing so. I bought some polystyrene from the craft store, and spent about a week cutting, filing, shaving, and sanding it to fit and to form just the way I want it. I covered the thin in bondo, smoothed it out, and it's all ready to be glassed for a mold.
Trouble is, I can't figure out a way to mount the damn thing onto the bumper when I'm done. Dammit. I molded it off the stock lip and had the styrene connected to it with Elmers glue while I molded. That aint gonna do, obviously, at 70mph or over any pothole.

So, how do I get this damn thing on my car and keep it there? Should I fuse it to the stock lip with fiber glass and bolt it back up? Is that strong enough? Should I glass larger on the edges than the mold and bolt those into new holes? Are there some clips of some sort you all may know of that will hold it without cutting into the glass too much? Pop-rivets? WHAT!? agh...its a bit frustrating. Despite a degree in ghetto engineering, I can't figure out a good way to get this thing mounted. Ideas? thanks.

wheel

I'd recommend drilling holes and bolting it in.Not many people will be looking underneith the lip, so it's not like it won't be hidden anyways. My friend has a Skyline type front bumper on his car with a lip you can put on or leave off and all he does is use 2-4 bolts to hold it on. He's one crazy driver and always seems to scrape the lip when he's turning in to his driveway or some parking lots; but it's still on there hanging strong. But maybe someone else will have some better idea on putting it on there better than just bolting.