Delivery man on the pick-up drive through and throw a bag at 'em
This is a reference to “the Re-up” in which a dealer’s stash is replenished with fresh supply. Since it has to be done in stealth to avoid the law, a brown paper bag is often used with a quick/discreet pass from one person to another. Lupe is comparing that process to the way that people go through drive-thru windows to get something that he considers to be just as poisonous in similar brown paper bags.
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