Yes Its True the Legal EXPERTS ?wont put a hitch on a USA wagon BUT in EUROPE its the NORM for a wagon to Tow a HORSE TRAILER
so A SMALL UHAUL Trailer wont be a Problem!

BTW have you had the TRANSMISSION SERVICED ?
Yeah I Know the (lifetime fluid) A JOKE!
I WAS a EX Factory MERCEDES TECH And I own A 2000 E class wagon (for my dogs)

I would say GO FOR IT!

And Where are You Moving to in CALIFORNIA?

Good Luck on The MOVE!