Quote: I think the rocker extensions look good. Not sure about the diffuser behind the rear wheels. Have you ever seen the LMC Super Cuda? The diffuser was in the middle of the rear valance.
My wife hates them too. I'll probably make them bolt on and off.
The placement is important. It keeps the air from spilling up from under the quarters. This disrupts and turbulates the air from the side of the car. The curve of the body really hurts the airs ability to "cling" to the boundary layer. It wants to "fall" off below the belt line. The side splitters "pick" this air back up. The air between the diffuser plates needs to make a clean exit from the back and merge with the air off the rear spoiler.
The Super 'Cuda was stupid unstable at just 200 mph. That car had a less than ideally designed belly pan (just a partial pan) due to so much "hanging down" and air was allowed to go pretty much as it pleased. They basically did no aero work to the car. The diffuser was cosmetic only. The front lift on that car is ridiculous. Watch the vids. The nose is 2" higher even at 120 mph.
