"Weaving" involves tires touching left and right side road lane lines within a certain distance. Of course they do not measure because when they get to your wide open window and they "smell marijuana" and the driver is talking up a storm you are screwed.
Never talk to police , roll your window down an inch. stay in your vehicle, if they order you out then get out but make sure doors are locked and keys are IN THE CAR. Say nothing, it is your Right. They must have a warrant, something illegal in plain view, or your permission to search otherwise evidence found will be "fruit of the poisonous tree" aka illegally obtained and thrown out of court. Talking to cops will not help you as they have tricks they use and you will be consenting without knowing it.