Hi, firstly chlamydia is a sexually transmitted infection and its not spread from not cleaning in a car. thats completly out of the question on how its spread. If your boyfriend has no symptoms of a white puss penis discharge and burning while urinating at this present time (as in all most all cases men get these symptoms) then its has to be a false positive. Also when a person has gono it would clear up by itself in a few months by the bodies immune system so it would not be present for 2 years.