In spite of the pandemic my (almost) 3-year-old is going to preschool and, because of the pandemic, I'm able to drive him there.
Just him and me in the car, his favorite CD playing and little traffic. When we stop in a red light he says:
"Stop papá, STOP! It's red. Rojo!"
And when it turn green, before any cars in front of me start moving he says:
"Go papá, GO! It's green. Verde!"
With also the occasional "Watch papá, WATCH. WHATCH THAT!" if there's a backhoe loader, construction vehicle o big truck, and the "Again again!" to listen to a son over and over and over again.
He is such a backseat driver, but I enjoy driving with him. He is incredibly cute. My father, on the other hand, was a horrible backseat driver. He would rarely be on the back seat like my kid, of course. He would be sitting next to me, the driver, and being continuously:
"Reduce cuando llegues a la rotonda. Frena. Acelera. No le pises tanto al acelerador. Cambia a tercera. Cambiate de carril. No te pegues tanto a ese."
He would get me nervous in the best case and angry at the worst (which in turn would make me to drive worse, getting even more commnents). It was specially annoying and stressful having him in the car when trying to park:
"Gira. Gira todo. Dale. Dobla. Dale más. Para. Gira. Ponlo en punto muerto..."
I think that we all have driven with someone who can't stop giving unsolicited advice or instructions when they are not the ones in control of the vehicle. In English they are called "backseat drivers" (despite where they are sitting in the car, back or front).
I don't think that the literal translation "conductor de asiento trasero" applies to Spanish.
What do call in Spanish that passenger who can't stop giving the driver unwanted advice?