From the Story
Discovered in Book 2, Chapter 3, The Burrow
"Ron arrives at number four, Privet Drive with his brothers Fredand George in a flying car."
Discovered in Book 2, Chapter 5, The Whomping Willow
"The flying Ford Anglia is a Muggle car that has had its interior magically expanded by Arthur Weasley. The Weasley family and Harry use the car to drive to King’s Cross to catch the Hogwarts Express. When the barrier to the platform seals, stopping Harry and Ron from getting onto the train, the boys use the car to fly to Hogwarts."
Discovered in Book 2, Chapter 15, Aragog (chapter)
"The flying car comes to Harry, Ron and Fang's aid when they are about to be attacked by Aragog's family. The car thunders down the slope with its headlamps glaring and horn screeching and knocks the approaching spiders aside. The boys dive into the car when it stops in front of them and it drives them away from Aragog's hollow to the edge of the Forest."