+1, filing a Police report may not be the best use of the police department's time. If you call RTD and you were parked in a RTD run lot they will likely take action. The property is not available to companies who put flyers on cars, they strictly forbid it. I've called and asked and the answer was no. In our case we only put something on a car when the lot allows it and we ask permission before we access any lot. We usually have a signed contract with the lot owner.
They company failed by placing the business card in a way that it would drop in the door. If they are reputable they will listen to your complaint and take appropriate action. If not they are no different than any other 2nd class business.