[tobiahr]

If you are trying to keep exhaust from coming in you have to keep the rear window shut. I've had both the the 45 degree pipes, rear dumps (came out beside the license plate) and even a set of side pipes that dumped in front of the rear tire. With all of these i still had problems with exaust fumes with the rear window down and strangely enough problems with the top off with the rear dumps. I have also had fume problems with leaking weatherstripping on the rear gate with rear dumps. Currently going with 45 degree pipes to avoid as much as possible. IMHO they look better too.