Update: Just installed the RA's (incredibly simple actually) and a steep driveway (mine anyway) isn't an issue. They don't even scrape.
I'd post a pic, but y'all know what they look like . . .
Installation Tip: This may be obvious to others, but it wasn't to me right away. When I pulled the side-skirts away, I initially didn't realize that it popped the clips off about halfway down the car and not just the front few, and I didn't pull them off very far at all. Not a big deal and it just needs to be popped back in to place, but I didn't notice at first that it had come undone.