A "six" is not a 6 cylinder car.
A "six" is not a top of the line mercedes.
When rappers refer to a "six" they are speaking about a six figure item (typically a car). Why the hell would Jay-Z rap about a buick, pacer or pinto (all of which are available in 6 cylinders)????
We all know a 20 is a 20 inch rim. It's on a six figure car, not a six cylinder car.
2) Check your six!
six is also a lucky number for some, as it defines the transfer towards something more real, and long lasting.
A girl who is Six is so serenatastic that she is probably is an android after all, and therefore most likely designed for one purpose in a virtual world.
And who could argue with that?