I made a tractor cake for 3's birthday party. It was so cute. I used a homemade devil's food cake recipe, and though it was good it really wasn't that dense chocolate that you are looking for in a Devil's food, so I won't share the recipe since it really didn't live up to what it should be, though when I do find one I will let you all know.
The cake took quite a while to decorate, but in the end it was fun and he loved it.
I used a Wilton pan for the tractor shape then just made my decorator frosting and colored it to what I wanted. It was fun, and I love the fact that he loved it too.