I have an open trailer (16 ft), pull with a pickup. I want to haul a coupe for some 80+ miles round trip. Will be on back highways for lower speed. One window rolls up. The other is down. Before, I have put my straps X'ed under the car looping over each axle. Pulling the rear axle to the front and front axle to the rear.
Should the car be placed backwards to the wind or to the front. I assume to not cover it in fear of rubbing the paint.

Make sure the top material is very securely fastened to the top wood. I have seen a couple of cars that had the material come loose and catch the wind on a trailer and blow the top off. They were original cars and also destroyed the headliner and upholstery. Beware.

I throw three 1" ratchet straps over the top and hook them to the running boards to hold the top down. That holds the top down so that it doesn't bubble up in the wind. The first time I hauled it on my open trailer I didn't do that and when I saw how bad it sucked up, I was afraid of losing it. The straps don't have to be real tight.