B15 Sentra (2000 - 2006)
I found this thread in the how-to section, Make a Front Lip - B15U.com - Nissan Sentra Forum, and figured what the hell. My bumper is cracked from those road gators anyways. Here's what I did.
1. Bought some plastic edging from Home Depot. They had a better kind but I went the cheapest...