B+ motorhomes

Had a nice weekend trip, had to use 2 sewer hoses, luckily there were 2 and a connector!!! It ran alittle uphill, so a challenge to dump, will be buying a cute little railroad track device in case this happens again. While observing my husband setting all this up, looked at all the dust collected on the rear bumper (dusty and hot here), located a BOO-BOO, did not make me smile. It wasn't there after our last trip as I had personally washed the back end, looked like some kid had thrown a basketball against the back wall, could still see the mark and many hairline to slightly larger cracks thus ensued, cracked the gel coat nicely. One reason to find a storage site instead of the yard I guess. Any comments on what to do about this??? :M