If you're planning to haul large vehicles or equipment behind your truck, you'll need to purchase a trailer. There are many solid choices today, and to help you make a good investment, you'll want to consider these buying tips.  Decide Between New or Used  In terms of a trailer's condition, you can get new or used. Both conditions can be worthwhile purchases depending on your specific needs. If you don't want to have to worry about inspecting the trailer before buying, then new models are the best option.