JTE_502

I have the Eibach 1.5" drop on my car right now, and I rub quite a bit on all the crappy roads around here. The parts I have been looking at are the Street Scene side skirts and some of the different front spoilers such as the CDC ones. Just wanting to know if anyone here has had any trouble running some of these items on their lowered cars, and the different brands that give problems. Also for the side skirts, do you have to take off the factory skirts to run the aftermarket ones, or do they just go over the top of the factory pieces? TIA