I also ran into an issue with having radio op plates on multiple vehicles. One year when I had my vehicle inspection done on my car they wrote it up as if they inspected my travel trailer. I didn't discover this until I got home and was going to renew my registration online. I ended up having to go back to the auto shop to get it sorted out. It took some explaining and re-explaining to get them to understand it. In the end nothing that couldn't be overcome. Just a minor inconvenience.
