Registering the trailer was just about the easiest step of the build so far. We had heard of nightmare situations at the DMV registering home-built custom trailers where getting the run around was par for the course. In our case we simply walked in our local AAA office, showed them the paperwork we had and the trailer’s Certificate of Origin, paid $47, and received a California Permanent Trailer Identification (PTI) plate. The PTI is good for 5 years and only costs $10 to renew. It turns out that utility trailers are the cheapest vehicle registration available at the DMV. Cheaper than a 6-foot Dingy CF tag even.