Pro Box
I also use the Pro Box. (My LHS has gotten a few) and although they are expensive (Mine was around $300+/-) they have made unpacking a thing of the past. All I have to do is leave the box next to my pit space. Unfold my towel, lay out my car and i'm done. Mine has a single plug coming out the back, so I just leave my charger and power supply hooked up during transport.
When you see this thing, the workmanship is amazing. He was behind on orders for a while, but I think he has since caught up. I know he had sold a few to guys who fly R/C planes and it has been very well received with them as well.