Secured to your trailer

Being in the car hauling business for over 25 years I use regular car carrier chains and winches on my trailer.
I try to do an outbound (A) pull if possible. I have seen guys that do an
inbound (V) pull and have actually bent frames on pick-up trucks.
You need to keep a small (fore and aft) angle at each end of the vehicle and a very small (side to side) angle.
Crossing straps is a HUGE liability as if you lose tension on 1 side, that end of the car can come completly off the trailer before the other strap can exert any tension on it.