I donate birthday cakes for kiddos at an inner city daycare in St. Louis. One of my boys has requested a cake with boxing & cars. I was thinking of putting boxing gloves in the middle and two matchbox cars also and then a race track around the sides of the cake. I am an old school buttercream girl, never worked with fondant. Any other suggestions?

You could do the boxing gloves on top and do your racetrack idea around the base of the cake on the cake board with the cars on it. 

That's all I can think of to make it not look so busy and incorporate two things that don't incorporate well together. haha! I love kids!