Ive towed a lot of cars with a tow dolly. For RWD cars, placing the front end of the car on the dolly and leaving the rear wheel on the gorund is the most stable, most of the weight in on the dolly wheels, helps prevent swaying. Now, for automatic transmission cars, all I do is remove the driveshaft from the differential and leave the other end (yoke) in the transmission so as not to loose fluid, I use a ratchet strap to secure the free end of the driveshaft to the under body of the car/truck, making sure it is not going to come out of the transmission while driving down the road. Never had a problem!