That looks awesome, Carey. Plus you can tell you actually use the truck.
I'm sure you can find a couple of airvents. I'm thinking something that mounts on each side with scoops pointing down to keep most of the water out.
Here's something else you could mount on the roof and has a motor.
http://www.pplmotorhomes.com/parts/r...-roof-vent.htm
Actually, I like this one better for the roof, and it's cheaper. ALOT!
West Marine Air Vent