Thanks for showing the pictures of the trucks and busses. It reminds me of Car and Driver's response to the challenge for magazine publishers to get the best gas mileage with the 1st Gen Insight. They modified an SUV and tailgated the SUV getting 150mpg at 55mph.
The part about trucks reminds me of Luigi Colani's truck designs. No info about cD and only focuses on front aero but it would be better than the bricks that drive down the road today.