Hi, I recently bought a aerosol spray paint from an auto body supply retailer to match the color of my mazda 3. I used it mainly to repair the damage done to my back bumper where i had a whole through it just under the license plate. I fixed that and so far so good it has nearly been a month. However a couple of weeks ago I tried to use the paint to touch up my front bumper as there a few stone chips under the fog light. It seemed to have gone well until I went on a drive to Toronto from Sudbury last weekend. Between the rain and driving on the 400 i had paint flaking off in a few different places. Any ideas why this would happen a week after i did the touch up?