Has anyone else had a problem with the plastic bumper below their rear fenders (rear quarter panels) rubbing and taking off the paint at the front edge of the fender just behind the rear tires. I have rust spots developing on my 04 Mazda 3 Sport GT on both the driver and passenger sides. I have brought the car to the dealer and they say that stone chips caused the rust and they can not provide warranty. When I push back the plastic bumper I can clearly see that the paint was removed from rubbing which must be caused by vibrations. I believe this is a manufacturers defect and am going to try to get my dealer to take care of the issue. I am very dissapointed that the car I love (and take very good care of) is starting to rust after only 3 years. Has anyone else heard of this problem? Any advice?