In People v. Russell (2000) 81 Cal.App.4th 96, an officer observed a car traveling several miles below the speed limit. The car drifted around within its lane and sometimes out of its lane. The officer followed the car for three miles and ran a check on the license plate, which did not reveal any problems. The officer, who had 15 years of law enforcement experience and extensive training in drug interdiction, initiated a traffic stop. ( Id. at p. 99.) When the officer approached the car, he smelled a strong odor. Based on the officer's experience, he believed that such "masking odors" are used to mask the odor of drugs. The driver of the car, Burks, said he was taking a Vicks tablet for a cold and that the odor was coming from that. It was the officer's opinion that the odor he smelled was not from a Vicks tablet. Burks produced identification but could not produce the vehicle registration because the car belonged to a relative. Burks's eyes were red and watery, but there was nothing in his manner or speech that suggested he was intoxicated. ( People v. Russell, supra, 81 Cal.App.4th at p. 99.) "The officer also made observations which in their totality suggested drug activity, including: the overwhelming odor (frequently used to mask drugs); the driver's unsolicited claim that the odor was a Vicks tablet (suggesting a possible drug paranoia); the registered owner of the car was not present (a ploy used by drug traffickers to try to create confusion as to who is responsible for drugs found in the car); one of the occupants was wearing a pager, and there was a cellular phone in the car; there were worn screws on the dashboard and the upholstery did not appear to be the original, suggesting the vehicle may have been disassembled; and the occupants were two men, from Los Angeles, where large quantities of drugs are brought into the country, and were headed north, apparently having driven through the night." ( People v. Russell, supra, 81 Cal.App.4th at pp. 99-100.) Burks was removed from the car and the officer walked him back to the patrol car to see if he was under the influence or involved in drug trafficking activity. "The officer concluded Burks's red eyes and slow gait were attributable to a cold." The officer questioned Burks. His responses and the manner of his responses were consistent with the officer's suspicion of drug activity. Burks sat in the back of the patrol car because he was cold and sick. ( People v. Russell, supra, 81 Cal.App.4th at pp. 99-100.) The officer then spoke with Russell, the passenger of the car. Russell was nervous and evasive, gave responses contrary to Burks's responses, and could not provide sufficient details for his answers. Russell was asked for consent to search the car; he gave his consent. The officer discovered a large amount of drugs. ( People v. Russell, supra, 81 Cal.App.4th at pp. 100-101.) The trial court denied the defendants' suppression motion and they appealed, claiming the consent to search the car was invalid because it was the product of an unreasonably prolonged detention. First, the court found that the erratic driving justified the stop to determine whether the driver was intoxicated. Next, the court rejected defendants' argument that the officer should have concluded his detention when he spoke to Burks because Burks spoke coherently and produced his driver's license without difficulty. The appellate court found that the officer still had reason to question the driver's fitness because his eyes were red and watery. The officer was not required to accept without further inquiry the driver's statement that he had a cold. Even though the officer determined that Burks's red and watery eyes were due to a cold, the officer had further information causing him to believe that the defendants were involved in drug activities. Thus the officer could prolong the detention based on the further information. ( People v. Russell, supra, 81 Cal.App.4th at pp. 102-104.) "The overwhelming odor, together with the other circumstances, justified investigation regarding possible drug activity." ( Id. at p. 104.) The court concluded that the detention was not unreasonably prolonged. ( Id. at p. 106.)