S.
If you have time... blow up a picture of Lightening McQueen, have it laminated (teacher's stores do this fairly cheap), make some wheels, put double-sided tape on the back & play "Pin the Wheel on Lightening McQueen".
If you're serving ice cream, at one point, Breyer's made a checkered flag ice cream. It was chocolate & vanilla flavored.
You can also play bingo & the "prizes" can be cars related, they even have Cars fruit snacks.
When my daughter was 3, she wanted a "Queen of the Racecars" party... she thought that was Lightening McQueen's name. We had a great time @ her party & I know you'll have a great time @ your daughter's