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Willwood System - Porsche Hitches and Bike Racks
I built my own because Willwood didn't offer a 2" receiver type that I wanted to match my bike rack. Mine uses the tow hook threaded hole and on a one off basis too complex to make economically.
There are other hitches I've heard of that use the bumperette mounting holes to attach but I don't know where they are sold.
Good luck. Please let us know what you end up with and if you like it.