Having a 'real' office adds credibility to your operation. It's also a place to direct deliveries and applicants. Without an office, you risk appearing to be just another trunk slammer.
Many HOA's, and even some towns, have rules against parking commercial vehicles - even a simple pick-up truck - overnight in residential areas.
Many towns also have zoning laws that forbid operating a business out of your home. Here, we even had a book author get cited for violating the ordinance - and lose when he challenged it.
Finally, being able to pull your truck inside at night has several advantages. Not only is there the convenience of stocking / working on the truck indoors ... there is a real security bonus.
