A guy on ukmkiv's is selling front and rear bumpers which have been smoothed. He wants £50 for the pair plus postage. However the rubstrips have been filled with fibreglass and then filler on top. This is the worst way to do this ain't it? Will the fibreglass just flex and crack? The rear one already has a little crack, which is curved like the edge of the rubstrip, which I'm guessing is due to the method used. Anyone here smoothed theirs the same way?