Green’s Dictionary of Slang

da land n.

[? da (i.e. the) land of nod n.1 (1)]

(US black/drugs) getting intoxicated on a drug while sitting in a car with the windows rolled up, thus intensifying the effects of the ambient smoke.

Luniz ‘Dict.’ at luniz.com [Internet] Da Land: Gettin’ High, In A Car Wit Da Windows Rolled Up.