So you have decided to purchase a vehicle wrap to help promote your business.
The next thing you have to consider is design. What do you want this new marketing piece to look like? First you should consider a concept called integrated marketing communication. The basic idea behind this concept is to present a cohesive brand image across all encounters your customers have with your business, in every setting. This means that your customer receives a consistent experience (in this case visually) with your company. So your website, physical business, and all other marketing material have a similar aesthetic that your customer can recognize and associate with your brand.
With that being said this concept also applies to your vehicle wrap. When considering your design and what you want your car to look like, the color scheme is a good place to start. Your color scheme should reflect colors that are recognizable to your brand and familiar and consistent with the avenues of interaction your customers encounter. If your logo has color in it consider selecting one or two colors from that as your base colors along with black and white. Think of Monster Energy, they are known for there black and green color scheme it is incorporated into their website, products, and their vehicle wraps. Now imagine they used a blue and yellow color scheme similar to best buy. This would be very confusing and it would probably take people a while to figure out that it was monster energy. However, when you see the familiar colors matched with the logo that you recognize you instantly know and associate it with the correct brand. This way instead people trying to figure out what your brand is, they can focus on the message you are presenting.