As it might help with your decision, the USA trailer hitch system is NOT the same as the CH/European one. I will not go into all of the differences but your bike rack will not work with a CH trailer hitch. Sell or leave your USA bike rack in the USA.
Just go with a strap mounted system (there are several models available) that will work. You just need to make sure that the rear plate is visible so when the speed camera flashes, it can see the plate

. This is just a question of setting it up correctly.