I just had a open trailer built. I had them make 20ft full diamond steel with 16ft flat and 4ft angled or slanted down, with 6 1/2ft ramps, 4 d ring tie downs, brakes at one axle, buddy grease bearings, and painted silver to match my car. Works great just drive on and back off with no problem and plenty of clearance. Its 82" between the fenders which leaves about 3 1/2" between car and trailer fenders. Drivers door opens easy with clearance.
It cost me $2,200. You might check a local trailer store and see if they can build you one. If not I could hook you up with the company that built mine.