One of my best memories growing up with my brother (not many, he was older lol) was playing cars. I think a car theme fits many ages!
Set up a great buffet with lots of goodies. Use bold black and white patterns to coordinate with your theme! I love the silhouette on this cake, too with one pop of color! Source
Add a little flare to mini burgers or sandwiches with checkered flags! I love the coordinating buffet cards, too! Source
Make traffic light cookies with red, yellow and green candies on a popsicle stick! Source unknown :o(
Add a little frosting to your drink station just by adding a "refuel" sign! Love themed signage! She even had oil funnels at the milk station! Source
Add white stripes to an inexpensive black table cloth, use green, yellow and red plates! Source
My FAV cake/cupcakes I found for this theme! How dang cute are these?!? Source, and here is a good tutorial for the race car.