Yea, an actual license.... If you are looking at hitches, you need to get one that is built for your car, and is rated to fit your car. Have you considered getting a hitch added, and a rear hitch bike rack?
It isn't recommended to weld a hitch to cars, as the sheet metal on the body is rather flimsy, and getting one mounted to the frame on modern cars is rather difficult. Most hitches you can purchase that are designed for your car attaches either to the sides of your spare tire compartment, or bottom of your trunk on the outside.
After looking around I guess you have an SUV, found a hitch receiver for ~$150 that bolts to what I would assume is your frame on the driver and passenger side, the hitch receiver it self is rated for 3500 pounds. Once that is installed you can buy the hitch piece you need for using it as a bike rack.
Look here to get an idea,
U-Haul: Trailer hitches and towing accessories
Just note, a hitch may be rated for 3500 pounds, but you still have to go by what your SUV owners manual or door sticker says for towing weights, and maximum load.