The windows roll down all I see is a hand pass it
They roll down the windows because it’s smoky in the car from hotboxing that all he sees is the hand of the homie passing him the blunt. Kendrick’s ability to only see the hand could be implying that he was only focused on the blunt.
This blunt is the same blunt that they refer to later in the song as “the wrong blunt.” Kendrick smoked a blunt laced with Angel Dust, or PCP. It is after this blunt that the album is named because one of two things that m.A.A.d stands for “my angels' angel dust.”
To help improve the meaning of these lyrics, visit "The Art of Peer Pressure" by Kendrick Lamar Lyrics and leave a comment on the lyrics box