Doctor in the House S04E14 - Honeymoon Special

As the Binghams prepare for their honeymoon, Paul and Dick get Lawrence so drunk he passes out and when he comes to they have encased his leg in plaster, telling him he broke it dancing on a table. Duncan has to drive the couple to their hotel in their car but due to the lack of trains must stay the night. Paul drives down next day to free Bingham but his car breaks down and Lawrence has to tow him. Unfortunately the plaster gets stuck on the accelerator and eventually the car stops on a level crossing. Lawrence is freed but the car is a write-off and Collier ends up with his leg genuinely in plaster as a result.