I did some digging. According to this guy, BMW did make a tow hitch for the e46 generation that attaches to the main bumper.

He refers to the following part:
https://www.realoem.com/bmw/enUS/sho...80#71606767756

This would be the best solution, and would conceivably give the ZHP massive towing capability >:D

Here is a link to the part (I think) on realoem.

I need to keep researching this. The ZHP engine, manual transmission, brakes, and tires, would make it a pretty excellent tow car.


More research, this time in the Vaterland. The Germany word for trailer hitch is Anhängerkupplung.

In Germany they seem to use this guy: https://www.amazon.de/Westfalia-Abne...0407994&sr=8-3

And it appears there is this OEM BMW one being sold on this website:
https://www.hubauer-shop.de/de/anhae...606767756.html

There is an asterisk here: "Auch passend für Aerodynamikpakete, Rahmen und Klappe für Aerodynamikpakete nicht im Satz enthalten!"
translated: "Also works for cars equipped with the aerodynamic package, however the frame and flap for the aerodynamic is not included with this kit!". Not sure what that means. I might give them a call and ask. This would be a pretty cool solution, although I'm not sure if the European balls work here in the U.S.

More research required.

Found a couple more options: https://www.kupplung.de/anhaengerkup...gerkupplungen/

These seem to offer towing capacities of up to 4,300 pounds with a tongue weight of 165 pounds.