My brother's birthday's in a bit, and I want to decorate him a cake... but....
Last year, I made him a cake that had gram cracker jumps, a sporty car jumping one of them, and some really good trees made out of kit kats and icing. He's really into mechanics, dirt bikes, four wheeler's and engines. I'm not very good, so I would like something a begginer could do. Oh, he's sixteen, so a kiddie think wouldn't work to well. Thanks. Rachel

A toolbox? Lots of examples in the gallery...it's basically a rectangle so a good "beginner" choice for a sculpted cake. Just do mechanics' tools on/around it instead of woodworking tools.

A car tire...kind of the same idea but round instead of rectangular. Or a battery?

If you'd rather do a sheet cake with decorations on top, you could use a chocolate mold to make wrenches and other tools. A chocolate-covered Oreo cookie makes a good car tire; you just pipe the wheel/hubcap on in the middle.

There are lots of dirt bike cakes in the gallery too, all sorts of different styles.

I was going to suggest a toolbox too. I'm a beginner myself and a toolbox was my 4th fondant cake. It was time consuming making the tools but straight forward enough to do.
I made a madeira cake in a square tin, cut in half and stacked it.
Good luck!