I'm using a 20' with the Driver's side exit door. (Actually measures 20' 10" inside with the bowed front.) There's plenty of room for my Chevelle. The rear axle sits just past the dovetail and leaves room to squeeze behind the car with the ramp up. Also still have plenty of storage room in front of the car since the front tires sit just behind the entry door. (A good 4'+ of free area in front of the car.) This probably wouldn't be acceptable for a race car, carrying tires, jacks, tool boxes, work bench, etc., but for general towing of the cars we see here, it has worked fine. My only minor complaint is that the driver's door won't open while inside the trailer because the trailer wheel wells are too high. I could put ramps on the floor to raise the car but for now I just crawl in and out the window. I think some of the trailers with torsion bar suspension have lower wheel wells.
Hope to have the winch installed soon so that problem is remedied.
That said, I wouldn't be at all unhappy with a 22' or 24'.
