Mike, we towed a Mini Cooper S manual transmission for 2+ years. We had no issues with the battery or transmission. It still is not a bad idea to run the engine every once in a while in neutral to keep the input shaft seal lubed. The other thing that is nice with the mini is the S model has run flat tires, so one less thing to worry about. I believe we used a Blue Ox base plate that did require some slight modification for the S model bumper fascia. Give me a call, and I can hook you up with the guys that rigged mine in Costa Mesa.
Steve & Rhonda Bennett
Dana Point, CA
92 Marathon XL40
2012 Jeep Rubicon Unlimited
Owner: California Coach Company, LLC