There was a wheel-tub liner, bolted on outer bottom corners (can you spot the rusty bolt that was hanging with just rot holding it up?) It had a curve downwards in its 3/16 or 1/4 inch thick plastic right dead center between the tandems. I had named it Lake Ditchwater... (on-board cistern)... Pity there were no trout swimmin' around in there! That became the catchment pond, so to speak, for the ideal mycelium habitat to start. The thing should have been lapped UNDER the outer skin like a roof shingle, not a gutter with minimal caulking to catch all water running down side of trailer. This was all hiding behind the crappy (I mean pretty) wheel flare decor screwed and cracked at every screw. A poster in another RV forum noticed every Tango, or copy of, at any campground she stayed at had a crack at middle screw, almost across the board. This piece is totally inadequate. A lousy lawn chair would do a better job but would look odd mounted there! Chair PVC is thicker, but how do I cut it up to match a tandem wheel opening?!! Any tips? Seriously, anything near the wheels should be skookum as well as leak-proof. "Water always runs downhill"... said that Newton dude, except when it wicks, of course. This liner must have gotten its shape from being at the bottom of the stack on a hot CA day, stapled and bolted in, then hidden with the pretty molded fascia. Read: sin-hiding house decor... I mean trailer decor... Also, fore and aft of wheels you will find the vapour barrier doubling as mudguard slash rock deflector. No chloroplast in the most vulnerable puncture areas. In actuality, holes here would have let the water drain. I think I will get busy with my awl, all over the bottom every foot or so, letting it breath in there with no chance of showers. It is bone-dry and warm between the frame rails where the corrugated PVC protects the underside. Should just start sleeping there, maybe. Hmmmm... From Soggy Stories, have a good one, PT reporting!