There are a lot of large improvements available for large trucks, aero drag reduction is a huge part of it.
Here's some new images of my CarBEN EV:
The roof just above the windshield is much smoother now; and there are two hard chines on the hatch; which I like because along with the "spine" on the hatch, they tie into the three hard chines on the hood and front fenders.
I am really debating whether or not I elongate the hood. like the 1/4 scale model. The foam in the front section was supposed to be 1/2" thick, but was in fact over 9/16", so it "grew". I like the looks of this, but I think the air flow of the shorter hood (in the SketchUp model) will be better -- because it will accelerate the air more quickly out and around the car, it then will close down more quickly, and this will help the air stay attached, and lower the drag, all else being equal I think?