backseat driver (also back-seat driver)

• 1. 

  N-COUNT If you refer to a passenger in a car as a backseat driver, they annoy you because they constantly give you advice about how to drive. 坐在汽车后座对驾驶员指手画脚的人 [表不满]

• 2. 

  N-COUNT If you refer to someone, especially a politician, as a backseat driver, you disapprove of them because they try to influence a situation that does not concern them. 干涉他人事务的人 [表不满]

  例：

  They accused the former president of being a backseat driver.

  他们谴责前总统是个专门干涉他人事务的人。