In your efforts to make life easier you will actually make it more difficult. If per chance you did "carry" a small car you would throw the balance of the MH off. The front end would lift and float on the road. You may also overload the rear axle causing damage.
What you don't understand at this point is towing a car makes driving a MH easier. It actually steadies the rear end of the coach in a cross wind. I prefer to tow then not tow for that reason.
Now as far as weight is concern you do have a valid concern. The heavier the tow the more brakes you need to stop it, and power to pull it up hills. I pulled a Saturn SC2 at 2,400 lbs and it was very aerodynamic. Other then stopping at the bottom of a hill you didn't even know it was back there. Later a brake buddy took care of that issue.
