if they say they smell something just say u dont smell anything. and if they ask to search say no and if they really want to search u they have to call for a drug dog to come and sometimesthats either too much trouble or it is not available at that time. this happened to a freind of mine. got pulled over and had been smoking in the car just before then. so it wasnt smokey in the car but it smelled. so the officer asked to search and he said no several times and they had to call for the dogs cause they knew he had something. and they waited like an hour and they never came and the cop came back and said they were on another call and he was lucky and free to go.