It depends on what type of flair and your wheel size.An example would be my car,it had the fiberglass gts flares pop rivited on when i bought it and the previous owner had cut the wheel wells tomatch the flare.he didnot need to do the cutting though because there was more than enough room for the tire with the stock wheel wells still in place.After i bought the car i changed it to gt5 flares and for that i had to cut the wheel openings up alot more because the tires are much wider.For fiberglass there are different ways of putting the flares on such as the poprivits,double sided tape fiberglassing etc.I would not recomend the fiberglassin of the flare to the body as the cars have a little flex and it will eventually crack.for a metal flare you need to either weld(the best way) or rivit the flares on.I went with the fiberglass flares and used the rivits from Volvo that they use to hold on there fenders.Its a larger rivit that has a rubberized ring that disperses the load so it doesnt distort the metal or fiberglass like a pop rivit might.the look cool too!The fiberglass is easy to work with and alot cheaper than the metal,but the best of the best would be the metal flares that are welded on.
