This is my take on the mini trailer hitch only with a mini trailer to go along with it.
No supports are needed. Since its going to be outside I would go with at least a 30% infill
Extra parts required
There is a hidden blind hole the all-thread goes into, to support the body of the trailer to lesson the chances of it breaking. I've printed several of them without supports but your mileage may vary.
There are holes to run a small zip ties, string, wire, etc to fasten the car to the trailer. In the image posted I have small zip ties going around the tires as if you would on a real car, but there are several options for holding it in place.
There is a support rod you can print and glue in place to give the tire some extra support if you wish to add it. Not a requirement but there if you want to add it.
The design is modular and was designed to use as little to no supports at all. The trailer glues into the hitch body. The most commonly used size is a 2 inch but measure yours to be sure. If you have one that's larger or smaller let me know and I can made adjustments for you. If you do not have a hitch pin then running a zip tie through the hole will be more then enough to keep it in place,
The author marked this model as their own original creation.