If not, you might be better off with your own coverage. If you have questions about coverage, call your insurance agent. A good agent will be happy to up their commission and help extend your coverage for a short time to adequately cover the rental vehicle. Face it, a 15' panel truck handles differently than a smaller family car. Decorating the truck Burningman has a very strict policy about vending.
Nothing is for sale.
They don't want any corporate logos and that includes rental truck logos. Hard I tell you. So you should think about ways you can decorate your truck and make it really stand out. The more fun, the better. Maybe you will cover it with a huge logo for your camp you painted on cardboard, maybe you'll cover the truck with fabric to obscure the ugly logo.