One of my favorite childhood memories with my brother is when he would allow me to come in his room and play with his race cars! Why are they just for boys?!? total crap! lol...
Don't forget about older (but still fresh!) frosting tips for race car theme, too!
How bright and fun is this setup?!? I love the red and white instead of black and white! and how simply adorable is that cake?!? Source
A little older take - hubcaps as a backdrop - awesome! You could pull this one off well into their teens! Also, don't forget to steal the idea of layering fabrics on the table setup - perfect! Source
Don't be afraid to use car things (unused!!!) - put them in the dishwasher and they are just like any other plastic or metal (unused!!!) item! Make it fun like this ridiculously clever drink station! Source
If the kids are young enough, have them bring their race cars, bikes, etc and set up a race then end with a car wash! How fun! Source and tutorial
Another fun idea is this racetrack tape! you could set this up all over the party! Source found via pedicurestopuddles. blogspot.com
And how about this adorable race car cake?!? The clouds are tugging at my heart strings! I love it! Source