I just call the DeSoto, The Old Broad. Usually after I've floored it and it downshifts, I say something like, "The Old Broad can still hoist her skirt and move when she wants."
I'm more likely to give my motorcycles nicknames, though. My 1979 Honda CX500 is called the Maggot cuz it's kind of ugly and my Russian Ural is called Arpok, which is a version of RPOC, which is an acronym for 'Russian Piece Of Crap'. My French mo-peds are called Phrench Pharts.
As far as my other half goes, her name is Cynthia. Because of stitches in my tongue at a young age, I have a problem of not being able to pronounce it correctly, so it's either 'Hey You' or 'Fred'. She calls me 'Bud'.