Question: At the end of the episode we can hear a truck reversing with a signal beeping and drill whirring, gear grinding - what was going on with Joe and Bonnie?
Answer: It's an exaggeration of using electric sex toys because Joe can't have regular intercourse because he's numb from the waist down.
Answer: Joe and Bonnie are getting intimate here I believe. It's showing what an ordeal it is for Joe to have sex, since paraplegics basically can't.
Answer: It's just a joke about what an ordeal it is to move Joe around when he's not in his wheelchair.
Bishop73