My son's 3rd birthday party is this Sunday and he requested a red race car cake with colored sprinkles and candies. I have a pretty good idea of how to achieve the red race car using red fondant, but I wanted to add sprinkles and candy to decorate the car and wasn't sure of the best way to get sprinkles and candy to stick to fondant. Should I pipe buttercream on top of the fondant and press the sprinkles into the buttercream? Any suggestions or recommendations would be greatly appreciated, as the parties on Sunday and I don't have much time for experimentation. Thank you.

I would use a food safe paint brush and use a little dab of water. Good Luck! Can't wait to see the finished product!

I just did a cake where I put sanding sugar on the fondant. I did a test on a small piece of fondant to check the color combo and I just used a little water to attach the sugar. It worked so well I went with that. I used a crumpled paper towel to swipe very litke water onto the fondant. Once the water had a chance to dry the sugar was stuck as if I'd glued it. Good luck!

Or you can paint on a light coating of piping gel

Sanding sugar and water did the trick. Thanks for the advice.