back seat

back seat
ˌback ˈseat noun
1. [countable] a seat at the back of a car, behind where the driver sits
2. back seat driver informal
  a. a passenger in the back of a car who gives unwanted advice to the driver about how to drive
  b. someone in business or politics who tries to control things that they are not really responsible for
3. take a back seat to accept a less important position than someone or something else:
    Finally, Bryant decided to take a back seat and let his son run the company.