[header] How to tell if you're being pulled over by a legit police officer [title] Check to see if it's a marked vehicle. [step] If the vehicle has police markings, it is highly unlikely that it would be an imposter. A civilian driving a marked police vehicle would most likely be spotted very quickly by an actual police officer, and that individual would quickly get arrested for impersonating an officer. 
If a marked police vehicle is attempting to pull you over, it's generally safe to assume that that individual is a real police officer. [title] Identify the vehicle's make and model.