It would depend on the kind of vehicle you are transporting. Open vehicle transport option is cheap but in does not protect your vehicle from dust, snow, rain etc while transporting your vehicle. Enclosed trailer vehicle transport meanwhile would carry your vehicle inside a cover while transporting it, thereby protecting it from the natural elements. This also makes it very expensive. So if you have an expensive vehicle like a sports car or a supercar to transport then the enclosed trailer option should be the one to go for. But on the other hand, if your car is a day to day normal car then you could go for the open air option.