From my experience with mine on (it's off for now until i can repaint it), the only main concern is approach angles for driveways, dips, etc...these things are fairly tough in my experience. people made them seem so fragile before, but mine has held up through some stuff. If you scrape, worry about the paint more than the fiberglass. No problems with speedbumps, but I did ram a parking block that I didn't see..that hurt.
