I'm riding shotty in a Magnum

from Das Racist – Who's that? Brooown! Lyrics on Rap Genius

Meaning

He’s got shotgun (ie, the passenger seat) in a Dodge Magnum.
The pun between shotgun and magnum (another type of gun) should not be ignored.

It’s a double pun — he also references Trojan Magnum, or extra-large, condoms. In this case, “riding shorty” has a sexual meaning.

To help improve the meaning of these lyrics, visit “Who's that? Brooown!” by Das Racist Lyrics and leave a comment on the lyrics box