I bought a non-running pick up a while back that had a cap and a drop in bed liner on it. When I went to look at it I checked the cap to make sure it had some kind of clamps holding it down. Between then and when we went to get it the seller removed the clamps and did not bother telling me. We got home with it and the wife looked at me with that baffled look and asked "There was a cap there when we left, correct?".....
Back in 1995,I bought a 1993 Nissan Truck and this guy at work really wanted the tonneau cover in the back of the truck.I told $100.00 and he bought it,took the clamps off the metal slide rails and back to work I went.
After work,I hopped on the freeway and was going 70 mph and I see this new corvette in my rear view come up to fast.The next time I glance and only see black,look again and I see my bed liner air borne and coming down on that vette.The wind caught it on time and blew it into the median.
I u-turned next exit and went and retrieve my bedliner and went home side roads at 35 mph,bought clamps next day.
Same truck,a week later,spilled gas when filling up and got red shop rag to clean my hands and threw it in the bed.I threw a cigarette out the window and into the bed it went.FIRE FIRE.
Melted that bedliner up against the bed...
So do not feel stupid,there is always someone stupid ER..