Sorry for a long absence on account of traveling overseas.
Back to the story…the wrapping or sign-age people (wrappers) are an integral part of the idea. They have the expertise to create the most amazing graphics to drape on a vehicle. It is this eye catching graphics that get the advertisers message across. If you have the graphics/images ready they can craft it into a wrap for you; If not, many wrappers offer services from design and artwork to printing and installation. Several wrappers even guarantee the quality of their wraps and installation + removal services.
To make it interesting, like the drivers, even the wrappers can engage in outbidding each other to win the contract per the advertisers terms. In short, we acknowledge the part wrappers play and that this idea would not go far, if wrappers are not a part of the equation.