I used an old nylon dog leash/ choker collar thing that my dog came with from the animal hospital after his leg surgery. Large dog, baggy skin. A traditional collar and leash setup didn't work for him.
Had a small 1/2" or so steel ring on it for the choker part. Fed the handle loop through the top and bottom sleeve, compress it down, and have a helper tighten it into a knot with a few clove hitches. Fed it up into the car and released.