We pulled a Mini Cooper S for two years with an American Car Dolly. Overall the experience was positive. The dolly is substantial and held up well over the time we had it.
Only issue we had was that we bought the brake controller and it was always too sensitive, even when the gain was all the way down. At low speeds the brakes would grab and on gravel campground roads they would lock up. I had a Tekonsha brake controller from when we pulled a trailer, and installed that in our motorhome instead. That allowed me to control the settings from the driver's seat and turn it off when we were in campgrounds. Not sure why the ACD controller was so sensitive, perhaps the Mini was too light.
One other thing you might consider is getting the heavy duty straps in place of the standard ones. We thought the standard straps were wearing and upgraded to the heavy duty ones after the first season. They did much better.
Last spring we decided we would rather pull 4-down and traded the Mini
for a 2017 Jeep Cherokee Trailhawk. It took me two hours to sell the dolly. The guy who bought it had an ACD for a number of years and had sold it. Then he regretted it and had been in the market for a replacement for several months.