The cast is shown driving in the 1947-48 Packard "Woodie" station wagon while the radio is playing music and the "unicorn" aerial is clearly in the down position in the center pane of the windshield. The radio would emit nothing but static with the aerial down.
In S01E10 (Full Circle), Atticus has his body/torso strapped to the spell cradle, but his hands and arms are not restrained. He is just holding some hand grips manually and could just reach over and unstrap the bonds.