back seat driver

Translations
пассажир, дающий советы водителю
He was being a back seat driver during the trip.
Он был пассажиром, дающим советы водителю во время поездки.
Definitions
A back seat driver is a person who gives unsolicited advice or directions to the driver of a vehicle, often from the back seat, and typically does so in a way that is annoying or intrusive.