The ATL fuel cell is mounted pretty far back in the chassis, Get Nutz Lab’s theory is that having the weight in back helps forward grip and helps the car generate angle. Since Forrest runs some of the biggest angle of any driver in Formula D there is probably merit in this!
The Optima gel cell battery is also mounted far back in the chassis in this really cool flush mount receptacle in the rear tubular structure.
You can get an idea of how far back everything is in this picture. There seems to be two schools of thought in Pro Drifting, centralized mass and having a large rear biased polar moment of inertia. Both types of car build philosophies are currently competitive.
The huge rear mounted radiator is a Ron Davis NASCAR aluminum part.
The rear bulkhead has the catch cans for the transmission and diff plus the fluid reservoir for the electric power steering system. The big aluminum thing is the surge tank for the fuel system.
The fuel system uses a Bosch 044 motorsports fuel pump as a lift pump that fills the large surge tank. From there a Magnafuel Protuner 750 high pressure pump feeds the engine.