这个短语的字面解释是“后座司机”，这是什么意思呢？请看对话：

    A: Jeff just asked for his assistant to be transferred to another position.

    B: Why?

    A: He said Sally becomes a back seat driver and it’s getting on his nerves.

    B: I think Sally has a crush on him.

    A: Then it’s definitely necessary to transfer her.

    Note: A backseat driver is a passenger in a vehicle who is not controlling the vehicle but who comments excessively on the driver’s actions and decisions in an attempt to control the vehicle. The term is also used for people who intervene with advice in affairs they are not responsible for, or subjects they may not understand well. Similarly, the phrase “armchair general” is used to refer to somebody who is not in the military but thinks that he knows better than the generals who plan military operations. This term can be used in many of the same situations as “backseat drivers.”