Is 'inside at the backseat' correctly used in my sentence?

Context: The principal was seated at the back seat while observing the Miss Cruise's class.

Every time Miss Cruise got inside the classroom to teach, Mrs. Carter, the principal, was present inside at the back seat to take observation notes.


No. He was sitting at the back of the room to take notes.

You can sit in the back seat of a car.


Thank you, Rover_KE.