Green’s Dictionary of Slang

(US black) a (high-priced) foreign manufactured automobile, e.g. a Bentley, Mercedes, Ferrari.

2012		Chief Keef ‘Diamonds’ 🎵 And I’m riding in them foreigns I’mma ride on St.Lawrence.
2016		Jeezy ‘in the Air’ 🎵 If you really ride foreign, three fingers in the air.