That's tough really as there is a pretty big debate. I've never personally used ABS, but I have used fiberglass on 3 seperate occasions and have no complaints other than slight modifying..especially in the license plate area, sanding, elongating holes. IMO, the factories are still the best option, the fronts can be had for pretty cheap, but the rears will kill you. Do a quick search on here, and you'll probably be able to find more info