re: What's the best way to strap a car down to a flat bed trailer?

Should have hooks imbedded in the bed. Use some tow straps. I put the one on the front into the a arms of my vehicle when I tow it. Find a piece to go thru in the front suspension. Something mounted permanently to the car. For the rear, I run my straps over the axle but make sure they are under the brake lines. Don't want to crush those. You can criss cross them but isn't necessary. Don't tighten them all down till all are in place and then do each one by one. Once you are on the road I would stop in about 10 minutes and check to make sure all is still tight. Then you should be good.

Into arrow pointing down?