^^^ same question as above. I am thinking about the flat bottom, diffuser design and its relationship to the exhaust muffler and exit. I am currently going to cut the rear bumper higher (so it doesnt act like a parachute) and the diffuser can extend a little longer. However I need to decide if I want the exhaust to run all the way to the back, and if so, exit out the center or tuck up and maybe come out the sides of the rear bumper...