Did you already own and insure a 5th wheel? If not, there was no policy that could extend automatic coverage for you. The comp and collision coverage will not extend from your truck -- only liability coverages. If you have a loan on that new 5th, I sure wouldn't want to leave without knowing there is comp and collision coverage on it. You need to re-contact your agent to see if there is anything else you need to do for coverage to remain in effect. If you have a binder, that is not the same thing as having a policy that will continue.