An article I found in today's Telegraph:
'About 7,000 US motorists have signed up to have their cars covered in adverts in "brand ambassador" deals worth up to £400 a month.
FreeCar Media, The Los Angeles advertising agency behind the idea, instructs drivers under a code of conduct not to smoke, litter or swear when behind the wheel. Drivers whose cars were recently wrapped with adverts for Coca-Cola were told not to be seen sipping Pepsi.
Car commercials are part of the trend towards so-called "guerrilla" advertising, whereby companies look for ways around consumers' growing resistance to conventional marketing tactics.
It is estimated that a single vehicle's advertising message can be seen by as many people as 70,000 people a day.'
The only problem I can see with this is that if it becomes a common thing, with already 7,000 motorists doing it, then it could become one of the conventional marketing tactics they were trying to avoid. Also, I can't believe that anyone, unless they were desperate for the money, would cover their car, that they had paid a lot of money for, in advertising!