I know there is no wood in the newer ramp doors. It's aluminum structural members with a foam core. If you opted for the patio option there is an additional thin sheet of aluminum to prevent pressure dings.
this has been brought up before . still have not seen any facts regarding a thin aluminum sheet in the door for the patio option . a thin piece of aluminum would not prevent pressure dings .
I welded an additional bracket in the top corner of the trailer to help support the cable, drilled 2 holes in the door and used a plate on the backside to distribute the pressure, then used cables and hardware to attach. Super east to make and not near as scary as I thought it would be. If you're throwing a spring break party you may wreck the door, but for 3-4 of us adults it looks solid!