You would think with the $$ you pay for a new trailer, they could put a decent mattress and bed in. First thing we noticed was how firm and cheap the mattress (Queen) was. I ordered an 8" foam mattress with a 5" base and 3" infused foam top. It made all the difference in the world and we just used the other mattress as the box spring. Yes the bed is a little taller, but makes it easier to "roll" out of.....
We did notice the mattress was a little long and I hated to remove the nice outer cover to cut some of the length off. The solution was to remove the headboard off the wall.....this would only work if you have the curved potion of the trailer as the headboard. Ours is a 5th wheel, so I popped off the headboard button screw covers, removed the screws that secured the headboard to the trailer (and the curved boards that supported the flat headboard - you know the vinyl wrapped board). I put all these parts in a bag and stored under the bed just incase a future owner wanted to replace it. The curvature of the trailer wall gave us the necessary 5" to make the foam mattress fit. With my husband being 6'2"....we needed the extra length.
The other issue I had was with the rough edge of the platform base.....seriously, why couldn't an edging be put on it. Before adding the foam mattress, my new bed spread actually got snagged on the rough edge. I purchased some of the vinyl tubing at Lowes, made a slit lengthwise all along it and took it from the area that the platform split to raise up....along the 2 curved end edges and to the other side. We used an electric stapler with short staples to secure the edges of the tubing as we eased it evenly around the edge of the wafer board. We started out putting a bead of clear silicone inside the tubing thinking it would help secure the tubing to the board but wasn't necessary and was actually a little messy. Now I have a snag-free and smooth edge.