When I had a dolly, our car did not have a locking steering wheel so I used a ratchet strap wrapped around the bottom of the steering wheel and secured to the driver's seat mounting bracket. After I was happy with the strapping, I cut the excess off of the ratchet strap and then kept it with the wheel straps.
One issue I had with the Master Tow. Make sure the electrical connection is secure where it passes from the frame to the turntable mounted fender lights. There is a quick connect there that separated on one side on mine and then got crushed during a turn. The other side was fine.