yeh they are above the £500 mark but not primered, so they need full prep before spraying too, my old IS had a fibreglass one on and it was rubbish, altho thats an accurate description of my driving too at the time, so it is no surprise that I cracked both the front and rear lip, the side skirts weren't made very well, I'm guessing so anyway as they were screwed on thru the sides of the car, ie, visible screws, leading me to believe that when they were attached along the bottom, they didn't meet the side of the car lol
DON'T BOTHER WITH THE FIBREGLASS OPTIONS :D