[j-c-c]

I've lost track here, is your shared experience with fabrics/vinyl's or rigid materials regarding belly pans?
Not sure cars can ever collect enough water to have ponding a serious concern due to size, whereas an RV/trailer/semi its very possible, and with their much greater load capacity the driver might never sense any water build up is occurring prior to failure. It is also a catch 22 issue, in that the better one seals the space to keep out water, the better it is to trap it.