To keep your wheel pants looking good, leave them off the plane unless it is a static display. taking off and landing in grass is the hardest thing on wheel pants so if you have a paved runway... stay out of the grass. If they crack the fiber glass ones are easily repared with fiberglass resin and a little fiber glass tape on the inside then just sand smooth and repaint. The ABS plastic wheel pants on the other hand once they crack you pretty much have to replace them because any repair you do will be noticable. But the good thing about the plastic ones are the fuel does not effect the color. The fiberglass ones on the otherhand some paints are more suseptable to staining from glow fuel... My Worl Models Ultimate Bipe's cowl was bad for that.