My boys are 2 and almost 4 years old and already they are completely backseat drivers. Carter is the law enforcement in our car. His Grandma B told him what each color means on the signals. He has decided that it's his job to tell me what I should be doing. The other day I made a right turn on a red light, Carter noticed and was appalled that I "went" even though Red means Stop. I spent the rest of the drive home getting scolded and trying to explain why what I did was legal to my 4 year old! It was actually pretty funny to hear his logic. Mostly I heard things like, "but Grandma B said red means stop. Mommy you have to wait until green turns on because only green means go."
Kyle on the other hand is our adrenaline kid. He likes the windows down, the loud motor, and going fast. He is usually yelling, "Go FASTER Mommy! FASTER FASTER FASTER!" He also mimics the sounds the truck makes, as if it wasn't loud enough already. A stop light is practically torture for Kyle, and he thinks I'm doing on purpose. "I can't go Kyle, the light is red" doesn't mean anything to his little 2 year old mind. He just thinks I'm not going to defy him. He's crazy!
Cameron usually sleeps through all of it! ;-)