I have them on my roadster. R1 is a good product. But, after doing the roadster, I realized how good the stock rotors are, so on the coupe, I upgraded the lines, the fluid, and the pads, and left the rotors. Both car perform about the same... If you are round tracking the car, and heating the brakes consistantly, then, drilled and slotted rotors are the ticket. Not necessary for us drag racers...but we do need to stop.