Ever since your trailer wasn't designed to get people sleeping in it, you will need to make adjustments to ensure it is safe.
Truckers drive for extended hours across long distances and they don't have all the comforts that we've got in our RV. In truck stops, it's much less so. VW Camper Van tents are fast and simple to prepare. If you wish to use the rear gate to go into town and prevent the highway get the combination from the workplace.