Legal Question in Traffic Law in Illinois

The officer can only testify to what he or she saw -- which was the cardboard apparently obscuring your headlights for a period of time while you were driving, which would be a technical violation of the law. You would have to testify as to the entire event, however, to show that (1) you did not put the cardboard there, and (2) you drove only so long as was safe to find a safe place to pull over once you realized the cardboard was stuck to the front of the car. There may be other facets to this that could affect the outcome including time of day, weather, the fact you had to be pulled over instead of voluntarily stopping sooner, etc., as well as whether your version of the facts makes enough sense for the judge to believe you and not the officer. If you need to keep your license free and clear of what amounts to a "moving violation" you should consider having an attorney go to court with you to contest this matter.