The "car way" of telling how far the relationship is:
-- Trying to impress the woman: unlocks and opens the door, waits for her to get inside, closes her door behind her
-- Dating: the guy unlocks her door and then goes around to his side to get in
-- Engaged: The man opens his door leans over and unlocks her door and opens it.
-- Married: The man gets in to the driver's seat, unlocks the doors, and says "Aren't you getting in?"