The Fast and The Phineas - S1-E4
Trivia: Jeremy mentioned that one of the cars' name was Billy Ray, making a reference to Hannah Montana , which country singer Billy Ray Cyrus stars in Mitchell Musso who played the voice of Jeremy also stars in Hannah Montana.
Answer: "One boring day, Phineas recognizes an important truth; Summer vacation will end, and the teachers will want to know what they did on their summer vacation. And with these two kids, it has to be something extravagant..."http://uk.imdb.com/title/tt0852863/.
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