The outer area under the DRL's is where I've had some scrapes, but this will be the case for any spoiler you choose. Both were my fault. Once exiting a gas station where there was a slight dip, and the second time I got too close to the curb when parking. You eventually learn to be careful and be aware of uneven surfaces :-)
Whatever spoiler you install make sure you get a clear bra or some type of protection against the rock chips. Even with a quality paint job it will get damaged. It's not nearly as durable as the plastic front bumper. I've already had to repaint. I found out my wife was driving to work through construction zones and they are scraping the roads!! Now she drives another route.
Here's what I'm talking about
