1. To have your car very low to the ground. Tucking tires, and minimal clearance between the ground and frame are a must. Lips, body kits, etc, don't count.
2. To be very drunk
3. To get fucked very hard
Basically, Nigger Slammed simply means, when one or more niggers carelessly backs-up their old piece-of-shit jalopy into a brand new, clean, nice 'White Man's' car. All because he or she is a stereotypical Nigger.
"Hey bro! What happened to the bumper of your new Challenger?!"
"Oh you know bro.. i just got Nigger Slammed yesterday!"