14' or longer get tandems. The items appreciate the softer ride. Like a boat, you get what pay for. The only one that comes to mind to avoid is the Interstate brand. I liked to paint the floor using traction paint and then install E-trac for tying things down. You can configure as needed. Look for secure gate and door latch. I used mine for a household move, dirt bikes, a RZR. The last ride was a trip from Arizona to Washington state and slept in it in April 2020 when open motels due to covid was far and in between.