Are the other drivers supposed to know John 14:6, have a Bible handy, or just remember the reference until they get home and rush to look it up?
I usually get one of three reactions...(1)They'll ask me what that verse is (Opening an excellent opportunity to witness), (2)They'll already know the verse and we begin a conversation about Christ (Which is very edifying to me), (3)No response at all.
Either way, I don't shove it down any body's throat but it does open the doors.