Yuma's a fun place in winter. Buttercup dunes to the west is a major off-road gathering Thanksgiving weekend and heavily trafficked in the winter months. Good dove hunting around there too. And Glamis is only a few miles north, for even more dune-running. Gets pretty chill out there at night though, but nothing like Alberta in winter. Better be IN the river in the summer though, 115F+ is common.
It would be easy to fashion some pre-set height extension brackets to raise one long side of a mounted panel to get your optimum angle, care with how you orient the vehicle when parking takes care of the rest.
I'm actually intending to use a 3-axis pivoting flat screen TV arm as a panel mount, within my rooftop mounting frame. I'll be able to uncage the panels and lift and orient them any direction to square them to the sun. Or undo a couple 1/4"-20 knob-handle bolts and detach the foldign panel for ground use out away from the shaded vehicle.