Scott Bennett wrote:From the CFD images in that gallery, it looked more like they were routing the rear fender vent through to the taillight vent, presumably to cut a little drag (dumping some high pressure air into the low pressure wake). If they are actually going to the brakes and the transaxle, then they are more "functional" than functional. Rear brakes don't need cooling on a road car. In the unlikely event the transaxle needed cooling, you'd use an oil cooler, since blowing air over the case isn't going to do much. Regardless of whether these vents actually direct air anywhere, they are for looks more than anything else.
It might be for aeroas well, but from what I've read their is a dedicated heat exchanger for the oil cooler for the transaxle in the back and one of those vents is dumping air through that radiator.
Point being, they're doing *something* even if that something may be not that important. Ex. The Corvette has had rear brake cooling since the C5 Z06, so it may not be needed on a road car, but there are plenty of Corvettes that do see the track, even if it's not the majority. They're not stick on gills like people throw on the rear quarter window of their Mustang to "cool the glass" if you know what I mean.