this thread is kinda pointless.
if a cop is searching the inside of your vehicle with a dog it's too late. you're getting caught. it doesn't matter what 'sequence' the handler follows. you only stand a chance if your weed is in a airproof container near the center of the car, far from doors n windows and the dog is sniffing the OUTSIDE.
if they don't have probable cause: that car is your fort.
doors have to be kept closed and locked, windows always rolled up.
the dog can sniff the outside of the car. the cop can't force you to roll down the windows, or to let that furball into your car.
if they don't have prob. cause, and you don't want to go to jail, or some other legal trouble: don't consent to a search. PERIOD.