Lightning McQueen (voice of OWEN WILSON) is a self-centered, rookie racecar who's about the hottest thing on the racing circuit. Battling longtime Piston Cup champion Strip "The King" Weathers (voice of RICHARD PETTY) and perpetual second place finisher Chick Hicks (voice of MICHAEL KEATON), Lightning ends up in a three-way tie with them.
That necessitates a race-off the following week in Los Angeles, but since Lightning is so self-centered, the only member left of his pit crew is Mack (voice of JOHN RATZENBERGER), his transport truck. The two then set off on their cross-country trek, but the long hours and darkness of night results in them being separated after both doze off.
While racing around in a panic trying to find Mack, Lightning ends up fleeing from the local Sheriff (voice of MICHAEL WALLIS) of Radiator Springs, resulting in a lot of damage to the main highway through the once vibrant town. As a result, the hotshot is locked away in the impound lot overnight.
When he realizes the young troublemaker is a racecar, local mechanic/judge Doc Hudson (voice of PAUL NEWMAN) throws out the case, but public defender Sally (voice of BONNIE HUNT) -- despite supposedly working for him -- thinks that Lightning should serve some public time fixing the damages and possibly infusing some outside interest in their town due to his fame.
With his gasoline supply limited to keep him from running away, Lightning reluctantly starts to work on the repairs, all while the locals watch. They include old tow truck Mater (voice of LARRY THE CABLE GUY) who befriends the sullen racecar, as well as hippie VW Bus Fillmore (voice of GEORGE CARLIN) and military jeep Sarge (voice of PAUL DOOLEY).
Old car Lizzie (voice of KATHERINE HELMOND) doesn't seem to know what's going on, while store owners Flo (voice of JENIFER LEWIS), Ramone (voice of CHEECH MARIN) and tire shop proprietor Luigi (voice of TONY SHALHOUB) and his faithful assistant Guido (voice of GUIDO QUARONI) long for any sort of business to come their way.
With time running out before his upcoming big race-off, Lightning can't wait to get out of the small town and back to his famous life. But as the days wear on and he starts to get to know the locals -- especially Sally and Doc Hudson -- Lightning begins to have a new outlook on life as he learns a thing or two about both himself and them.