There should be a clear difference between the easily-available car decals that civilians might obtain on their own, and the official, recognized vinyl car wrap that fits onto police cars. Aside from featuring the correct logo, symbols and colors of a particular department, the real police car design should be a strong one that prevents any confusion among onlookers. Working with a custom designer will help them make logos that are memorable but also authoritative.
Distinguishing between legitimate police cars and imposters, intentional or otherwise, is a serious task. Some decals out there will fit the basic requirements of a police logo and look the same, at a glance, which means that departments need to put special effort into creating a series of elements that sends the right message and clearly isn't faked. In fact, if the logos on a police vehicle are easy to imitate, it could mean that the current look is too generic.
In a Question and Answer column for the Michigan City News-Dispatch, Sergeant Chris Yagleski responds to one anonymous questioner who asked whether or not it was advisable to use promotional stickers related to the Transformers film franchise that said POLICE in large letters. Sgt. Yagleski answered that they could indeed be a problem, and compared this situation to impersonating an ambulance.
"Also in putting any decals on your vehicle that state 'Emergency 911 Response' it can be interpreted by the general public that you are a trained emergency responder," he said. "I would like to remind all drivers there is a fine line when it comes to 'impersonating a police officer or police vehicle' and we, along with other departments, do not take it lightly."
Both the content and the quality of police fleet wraps set them apart from other, less professional options, and police departments should only employ those visuals that are going to give that clear stamp of authority.