Shooting from the hip, my thoughts go to a either a superlight truncated boat-tail, or super-light, full-tail, one-wheel trailer, attached as Burt Munro's bumper-mounted 1920 Indian Streamliner, with zero-rake at the front fork pivot, and connected at the axle shaft 'pivot.'
My second trailer was done this way, except if had a bit of rake, which caused it to 'lean' during turns.
Since Moby is probably 'taller' than it is 'wide', you'd use its width as your reference for the streamlining, rather than the roofline.
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An aluminum skeleton for either, could be fabricated at a commercial awning company.
The stretched-skin covering, likewise. They use hypalon-impregnated aerospace fabric like GOODYEAR used on their blimps. It's UV stabilized and will last for decades.
It would be like an early doped- fabric-covered tail-dragger aircraft. Extremely light for it's 'visual' mass.
I have the rear wheel, swing-arm, hydraulic disc brake, and mono-shock suspension from a HONDA Hawk sport bike I'll be using for my next trailer. The trailer would be so light that trailer-brakes wouldn't really be necessary.
The tires are radial, DOT rated, and already have the load rating necessary for a superlite. Mine's a Dunlop, already speed balanced.
With drop-down 'pogos' ( Lockheed U-2 Dragon Lady ) either the boat-tail or trailer can be handled by one person at a campsite or RV pull-in.
The boat-tail could be double-purposed as an auxiliary sun-shade awning, or 'tent.' Same for the trailer body.
The trailer COULD carry light, fluffy gear, like sleeping bags, pillows, and bedding, but it's prime purpose would be fooling the air into thing that Moby is a SMART car.
Just some thoughts.
