I wouldn't start a business because I owned one type of vehicle. That simply doesn't make sense. You start a business by creating a business plan based on an idea that attracts customers to your solution for a problem they need to solve.
Many businesses use Vans... just look at the vehicles on the road as you drive around.
Mobile Oil Changers, Mobile Installers - Television, Stereo, Satellite.
Commercial Carpet Cleaners
Airport Shuttle Services
Disabled Persons Shuttles
Plumbing and Heating Contractors
The list is expansive.