There really isn't much more to the time machine other than the plutonium intake (or Mr. Fusion) and the cooling columns on the back. Add that and maybe a thick wire that runs from the back to the front of the car on either side and you're good.
Not just that. Theres also the "Bumper things," some scientific equipment on the top behind the doors, a few things where the window by the engine would be, and theres a crazy interior
Just to name a few things