I agree with Fabr on the tongue weight. See what it is before adding bandaids. With your 20' will you have room to move the two vehicles at all? When hauling a single car on a car trailer, I have never had a weight issue. Just park it as needed for the tongue weight desired. Trailer brakes recommended if loading for minimal tongue weight. The worst situation IMO is minimal tongue weight and a heavy trailer with no brakes. Disaster waiting to happen.