With an equalizing trailer hitch and lift bars you can tow a trailer with a fairly heavy load (like a car) and it works fine with a lowered vehicle. I have done that lots of times and had no problems, just be careful when towing even with trailer brakes it takes more time and distance to stop the extra weight. My car trailer has about a zillion miles on it and I have never had any problems with it, loaded with as much as 14,000 lbs. or empty.
