There isn’t one useful fixed price for this because size, materials, quantity, access and installation can change the job enormously. My preference is to price the actual project rather than throw out a number that may send you in the wrong direction.
If you send us a photo of the site or vehicle, approximate dimensions, your logo or artwork, quantity and location, we can normally narrow the options down quickly. And if you have a budget, tell us. It genuinely helps us design around what is realistic rather than presenting an option that was never going to fit.