(at around 33 mins) When Maurice stands up in the back of the car to deliver his lines of Shakespeare, a large patch of open space above the top corner of the wall can clearly be seen for almost 10 seconds, revealing that there is no ceiling. (Follow the corner line directly above the driver's head.) A piece of equipment can also be seen, as well as a hinge or angle iron near the top of the corner that allowed the two walls to be separated for the immediately preceding shot of the car entering the living room.