I don't do a lot of high speed runs, therefore the pans are off the car for good. The roadster has seen 160 with and without the pan...absolutely no difference in handling. I like the quartermile stuff...but, ask yourself this, unless you live in Kansas, Nebraska or Utah...just how long are you going to run 160 plus...I like the engine bay to rid itself of heat, and the pans stay off...with that said, it is very important to sustain high speeds, to control the air flow under the car. Anything hanging down will cause turbulance. The lower the better. The flow under the car is faster, and creates downforce. Take a piece of paper, fold each end by a third making 3 sides. Sit it on end as to make a tunnel. Have a little bit of air blowing down on the top, not enough to collapse it, but just enough to hold it down. Then with your mouth, blow into the tunnel and see what happens.