if you're just doing that for photo shoots, do wat i did. get some black hard felt, cut to size, and put thin magnetic strips on them to attach to your frame.
ive accidentally tested it up to expressway speeds and it did not come off. lol
yah, forgot to take them off after photoshoot. i was like
when i got home. hahaha. check out my albums pages for the picts with black felt covers.