Aluminum flatbed spread- with or without lift axle?

[Lonestar10]

always kinda wondered to how a set of side skirts like vans use would work to. also debated taking my great dane and getting just some thin but durable plastic sheeting and riveting or bolted plastic under all my bed rails to reduce any drag there. while still keeping the pockets on the sides open so i can still wrap my straps through the rub rain and hooking under the bed on the inside of my side rails. i see alot of company drivers wrap around the rub rail and hook to it which im pretty sure isnt legal in the book and i dont beleive the rub rail is made for that purpose my great dane has stickers specificaly stating not to do it as its a light rail.