Quote:

I don't cross in the back. If a strap were to loosen the car will move toward the tight strap if they are crossed.



This is illogical if you think about it. If the staps are not crossed or at least angled, this can allow the car to move from side to side even if both straps are tight (parallel arcs). If the straps are parallel and one strap loosens, the car can go still to either side. At least if the straps are crossed and one strap loosened (intersecting arcs), the car can really only go to one side.