We just got back from a rally, where there were 3 Fleetwood Heritages parked in a row. Each of them had a bulge in the GRP, on the nearside rear, just in front of the top rear marker light. The owners had not noticed, it was only when one of the ralliers noticed it on the one and then looked at the others and noticed they were all the same. One was not as bad as the other two, but also had a slight bulge on the oposite side as well. It looked like the timber inside was badly shaped. The owners are all going to have a word with their dealers about it. Maybe if any other owners have a similar bulge, they should all do the same. If there are a lot out there, then Fleetwood might take some action.
I don't know what this bulge looks like or exactly where it is, but could I suggest you maybe look at what is on the inside of the caravan at the same point.
I don't have this model and am not affected, it was just pointed out on Sunday morning that three identical caravans all had the same bulge. It was only that the sun caught one of them at the right angle, that someone noticed the bulge on the first one, then took a look ad the other two and they were the same. It looks for all the world like someone is inside pushing the GRP with a screwdriver. Inevitably the gel coat will crack sooner or later under the pressure.
When i was looking to buy a new van (not brand new) i came across this problem . from what i could see it looked like the bulges had been coming from the rear bunk bed mounting's that where on either side at the rear . this was on 5 berth vans
It was if some kid had been jumping about in the bunk , and flexing the sides of the van .
the newer vans i looked at had a different way the bunk was set up (not attached to the side's) and all had no bulges
Just got our van - it has a slight bulge on the offside in line with the shower rail (on the inside.) It was noted on the PDI form in case of problems in the future. It can only be seen as you said earlier when the light hits it just right.