A 21-year-old female student was arrested at 3:35 a.m. Saturday after police found a small bag of cocaine under the driver's seat of her car during a traffic stop at Harrison Avenue and Trowbridge Road, MSU police Lt. Scott Beckner said.The "white powdery substance" was spotted by an MSU police officer after he pulled over the student's Chevrolet Cavalier because, according to Beckner, the officer could not read the license plate and suspected drunk driving.Upon further investigation the driver was found to be operating under the influence of alcohol, and the male passenger was arrested for obstructing justice from an outstanding warrant out of Meridian Township.Beckner said the suspect was arrested with approximately one to two ounces of cocaine. She posted bond and was released. Beckner said police will seek a warrant for possession and will be assigned a court date at 54-B District Court in East Lansing.