Many months ago I learned of a girl who advertises her business with car magnets and vehicle card pockets. She buys her car magnets off eBay and the vehicle card pockets from a company in Canada.
I bought the vehicle card pockets for my own car but have not yet put them on my car. I am also shopping around for a place to buy my car magnets.
This is an inexpensive way to get your name out there. The vehicle card pockets have a flip top lid to keep your cards out of the harmful effects of rain, sleet and snow. However, it is advised that you purchase coated business cards since uncoated cards will fade from the sun.
Below is the link to the vehicle card pockets. You can see that they stick on your car (with apparently harmless adhesive). Your business magnets will be seen by anyone who sees your car. The cool thing is the card pocket. It really attracts attention. The benefit is this; when your car is parked in the mall or grocery store and someone sees your magnet and cards, it is easy for them to just take your business card. People don't always have a pen and paper handy to write down your business info so having the cards accessible is a real plus.
I asked the girl if she had trouble with people *cleaning her out of cards* and she said no. I was concerned about kids taking all the cards. (you know, just for fun) She said she has never had a problem with that and she's had the magnets and card pockets on her car for 2 years.
I'll post a photo once I get my magnets and card pocket on my own car!
See the pockets here:
http://www.vehiclecardpockets.com/