There's a point in model file named "misc_a". I added this point to sweeper model file, because I saw this in baggage and utility van dff. When I replace my model to baggage, so misc_a works, trailer connects. But when I replace my model with "misc_a" in model file to another car like cheetah, sweeper or something that's normally without trailer, so it doesn't work. Trailer doesn't connect.