Does anyone know an animated film about a boy who goes through door becomes cartoon in little red car and its magician maybe?

You are probably thinking of the 2001 animated film *Spirited Away*. The film follows Chihiro Ogino, a young girl who becomes trapped in a strange and magical world ruled by spirits. She must work hard to find her way back home, and along the way she meets a cast of colorful characters, including Haku, a mysterious boy who helps her on her journey, and Yubaba, the powerful witch who runs the spirit world.