While driving, a driver you spot on the road with similar license plate characteristics as your own. Such as same letter combination, number combination, or same state (if you are traveling)
Adam: Who would've thought we'd see another Idaho state license plate in Quebec?
Tom: you're right, I guess that makes us plate mates!
Tom: you're right, I guess that makes us plate mates!
by Tom Kesler June 20, 2010