Inspired by MetroMPG's aeromod thread, I decided to go ahead and try an air dam on my own car. Looked around for some materials, and ended up just about giving up when I found a 6'x3' sheet of coroplast at Home Depot, so I grabbed two and headed home. It's fully reversible, using 3M auto molding tape and corner braces to mount the coroplast, smoothed out with Gorilla tape. Since it's white coroplast, I used some matte black Plastidip for a quick paint job. About 2 hours of work to install, no testing yet.