I can see the dual purpose of the socks loaded with sand. You can whack the person who turns thier radio on your channel with them when they shoot you down.
I have a Toyota excab truck with a topper on the back, and a bedliner that had molded in recesses for 2x4's in it. I cut 2x4's to length, wrapped them with short nap carpet, and use velcro tie wraps to secure the fuses. Also have roof racks on the top, and have bungees running across the ceiling to hold wings if I need the area on the floor. I have put up to 5 planes in the back at once by taking wings off, but can easily leave the wings on all three of my planes (magic3d, .25 extra, and a majestic), and point the tails upwards, kind of stacking them against the row behind them. Can double deck it with wood runners across the top of the bed and haul more. Also ran a 12 volt fused link to the bed, and hooked up a 3 cigarette lighter outlet, and two sets of banana plugs. Have that connected to the 12 volt feed with a Tamiya connector so I can take it out to haul the usual truck stuff. Great thing about the bedliner is dont have to worry about the exhaust dripping. Great thing about the topper is that its weather proof, lockable, and a 12 volt charging station. If you can afford those two purchases, they are worth thier weight in gold.
Steve