It's not a bad idea to advertise on your car, in fact it's a great way to get your brand out there while parked or stuck in traffic. However, more and more people are catching on to this idea, and it's becoming annoying for consumers to see the same old ugly painted cars all the time.
This Sushi Car (pictured above) is a breath of fresh air, with a crisp and colorful design that cleverly employs the circular tire to mimic the shape of a sushi roll. The ad is designed so the viewer is initially intrigued by the tire design, and notices the small but prominent (bright orange) restaurant banner immediately thereafter.
So think up your own creative scheme to attract attention to your car, and then redirect the viewers' gazes to your promotional sticker, which you can place on your bumper or rear window. My only advice is to make the address or number to call slightly more visible on the ad!