I know what u mean! Even at stock ride height the F10 M5 is in danger on hitting curbs that are higher than others. I plan on lowering mine as soon as the Eibach Springs come out , but one way that I alleviated this problem is I bought some Tracwrap and cover the entire underside of the front bumper with it. My front bumper is clear-bra'd but the template does not cover the very bottom of it. The Tracwrap works great, cause its also clear but it's 3 times thicker than clear-bra. Plus it's easy to just replace if it gets scratched.
I've already had one occurrence when I was pulling out of a steep driveway out of a gas station front ways, and I scraped the bottom of my front bumper but the Tracwrap totally saved it!
I will say that it did take me a little while to cover the entire bottom of the front bumper as I had to take time and cut small pieces to get uniform coverage. It was a fun little project though, and no one can really tell that it's there because it's on the bottom and its clear.
If I were you if wait til your bumper gets a little more beat up then respray it, put a clear-bra on and put Tracwrap in the bottom, and most importantly park far away from curbs and those damned cement parking spot bumpers!