plates
My truck has log farm plates here in michigan. I had to get the truck weighed and take a weigh slip in to the SOS. They will then change your title so that it shows a weight right on the title. You do not have to prove anything to them as far as why you want the plate. You are, however, limited to the distance from home you can travel with the vehicle and you are supposed to be using the vehicle for farming, logging, etc. I have a buddy that has totalled trucks with farm plates on them while attending college hours away from home and was not questioned by the police. Lots of grey area.