Easy peasy. It's in a box. Wrap it.
The guy fix: Go to Home Depot where they have the huge rolls of paper with which to line your vehicle for protection. Roll out enough to wrap the box twice over. Put it in your vehicle as if you're going to load something atop it. If an employee asks, advise them that you need to see how the paper will protect your vehicle before you decide to make the purchase. Move your car (ostensibly to allow another customer to easily get their vehicle papered). Go inside. Buy something (light bulbs). Leave. Wrap the awkward boxed mop thingy in the brown paper. Draw festive figures on it with colored markers or crayons. Add ribbon. Viola.