Ok so I just washed my car. After a few hours of driving, I notice there's already a thin film of dirt/grime on the rear bumper and the vertical portion of the trunk lid. After a week, there is enough build up for me to have to usually wash it again, even if the rest of the car is completely clean. The build up doesn't occur anywhere else on the car. My theory is that it's caused by grime on the road being sprayed up by the rear wheels onto the back of the car. On the flat white paint, it's *really* noticable, especially when it's sunny. Has anyone else noticed this or had this problem? How do I get around it? Hyundai don't offer any aftermarket mudflaps and they would probably spoil the styling of the vehicle (unless they were body-colored).