Like Hemi71 said-- equalizer bars are highly recommended, but if your trailer is heavy enough-- (ours was 1800 lbs empty) perhaps thats not necessary.. We towed with the Ram all the way from atlanta to carlisle with this setup and it was rock solid.... not the slightest fishtailing even at high speeds and many bumps and turns.
We used high strength straps in an "X" configuration in front and back. worked perfect. Turnbuckles/straps in "x" configuration in back... tied to the leafspring/brake areas in the back and then used 2 Ton winches to pull the car forward until locked down usiing the lower control arms in the front. That allows the car to be locked to the trailer yet allows the shocks to absorb energy from the cars inertia. see pics below.
I use to do the X on the tie downs, until i talked with a manufacturer of the nylon tie downs. These tie downs are strongest when subjected to a straight pull. If you load them at an angle (as you do when you X them), they are not as strong when loaded that way. I now tie down my car without crossing the tiedowns. In the rear, i use the factory frame rail tie downs, and in the front i use an axle strap around the lower control arm.
You should always check your car on the trailer every 100-150 miles or so, make sure all the straps are tight. I alway check after the first 20 miles of driving, and the straps are always a little loose, just from the initial settling of the car on the trailer. Every time i stop for fuel or food, i check everytning...straps, Eq bars, safety chains, thump the tires, sway control, etc... never can be too safe.
And BTW..the heavier the trailer, the MORE you should use EQ bars.
