[euromodder]

Whatever its merits, I've always felt Phil's solution was way too complex to work IRL.

It's got to be done the easy way to work - KISS.

* Optimised for straight line duty and slight turns, i.e. highway style driving.
--- Don't bother about streamlining in slow hard turns

* Gap filling plates hinged on the tow vehicle
--- outboard movement to be restrained by bungee cords
--- inboard movement physically restricted by solid stops, yes, this will leave a gap on the outboard side in a hard turn - that's not an issue
--- downward movement of the top plate to be physically stopped by the sideplates , upward restrained by bungees
--- bungees might be fixed to the physical stops for the gap-filling plates, but not too far aft on the plates in order not to bend these.

* front side and top of the trailer to be rounded
--- helps even without the gap-filling plates
--- rear end of the gap-filling plates to rest on the rounded front, using teflon wheels on the plates
--- small, locally applied teflon plates on the trailer where the above wheels go as the plates slide over the front of the trailer