Commute Wife: that person you see every day in traffic at the same time, or same intersection because of your similar path to work.
While in most cases, this could be someone you find attractive, it may not always follow that rule (after all, you only get to see them from the torso up)
Joe: "Man, I haven't seen my "commute wife" on the way to work lately. She must be out of town or something"
Bob: "yeah, or maybe she got fired, bro"