Have a 2002 GTS, there is some type of vortex going on behind the rear bumper when the car is up to speed, like a low pressure area. Living in Florida this puts lots of sand all over the back, which I know could mess up the paint. The only thing I can think of to decrease this is a rear diffuser which mounts under the car. However they are about $1000. Is there anything else available that is cheaper? Thanks.