Or instead of painting it out you could just tip down until the top of frame lines up with the roof of the car. I would try to get an aerojib or aeroecrane in jib mode and mount say a libra head to it. You should be able to get away with a Fisher centermount kit possibly bolted through a couple of layers of 3/4" plywood or a large aluminum cheese plate . Rest it on some high density foam on the actual roof or build a pipe rig to mount it to the roof rack.
Backwind the cables a coupe of turns reverse of the action and direction desired and get somebody brave enough to stand on the roof and step over the jib or rotate with it as it makes it's turns. If the grip wears a harness and isn't a complete idiot, it should be fairly easy and safe. Bear in mind turns add inertia so he would need to brace/prepare for corners.
I personally would totally try it if you asked me to do it.