Vehicle is being monitored sticker/decal??

Hello im asking if anyone knows where to get those "WARNING this vehcile is being monitored" stickers or decals. Ive checked everywhere, google,ebay, auto shops, but to no results. Ive seen one on a car before and would like to know where to get one.. why you may ask? because its for my father, people are denting his car on purpose and making scrathes and doing unacceptable things at his jobs parking lot and dont ask if he went to secuirty because he did and it wasnt caught on camera even after numerous things happened to the car, i will not give out any info of his job for his own safety. So i would like to know where i can get one of these stickers or decals a site would help where i can purchase one any help will be appreciated. Thanks.

[edit on 1-2-2005 by ShadowMan]