OK here's a response, with graphics.
I guess it's more of a question,
You state somewhere in here that the wheels of the vehicle should rest on the ground plane.
Yet you say that flow separation occurs at 4 seconds after midnight.
It seems to me that these 2 statements contradict in the sense that air will either remain attached to a given shape until it reaches 4 seconds past midnight (115° beyond stagnation) on a curve (Red), or, you need to overlay a huge wing section onto a given vehicle (Green), and if you fall below this line at any point, you have flow separation, even if it occurs at some point less than 115° (which in this case is on the ground 20 feet behind the truck).
Which one is it? Red or Green? Or am I missing something? (Again, as usual)
