This object is quite simple to make but it needs some subtleties.
First you need a little toy-truck (made of plastic)
You need also the dock adapter provided with you ipod and a cutter.
The first thing to do is extend the slot of the adapter in order to put the socket (without that you'll have some problems to keep it in place).
Dismantle the little hooks on the socket.
After that, make a hole on the roof (dont forget that they are little pieces of plastic which are very useful to lock the adapter on the roof).
Stall the socket with some carton, cut a hole in the side of the truck for the wire.
Design a nice new painting for your badass truck...
You're done ;)