I would still presume most parties would declare unable to build a government than build a coalition with AfD.
My fear is that they actually get that strong they could lead a minority government (Minderheitsregierung). But I still believe in it’s not being that dumb again.
Actually, it can be useful in the car to send a message to someone like „I’ll be there a couple of minutes late“ or „shall I bring home something?“ without distracting yourself.