Lightning McQueen has been busy training all day that he is all dirty now. Now, he really needs to take a bath, but he can't do it alone. He would need the help of some human to make him clean and tidy all again.
The game is played via mouse and this game is interactive. Wash him first to soften the dirt all over his body. Put some soap and rub it to him gently. Water it to wash teh soap all over his body. Put some chemicals and police Mcqueen. In time, you would see McQueen back to his old self.