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The car car uses an nSPA Techniques FireSense AFFF Aqueous Film Forming Foam fire system. Instead of using a gas like Halon, the system uses a foam extinguishing media. We wonder how hard cleanup will be with this agent. The system is used in WRC and F1 so it must be pretty good. Check out the dimple die gussets coupling the roll cage to the chassis at the roof line, C-pillar and B-pillar.
The cage sits on sturdy box gussets that couple it directly to the frame rails. 
ARC components are used for wiring with this ARC power distribution module handling all of the electrical control duties. This module communicates with the roll cage mounted membrane switch panel show previously through the ribbon cable. While not your Mil Spec, Raychem and PDM level of wiring that some cars have, using ARC is a sanitary and less expensive way to do decent wiring. 
The lightweight dash has some ports for data logging and for ECU comunication with a laptop.
This door bar extension is something all drift cars should have, it gives a crush zone for hard side impacts away from the main cage tubes and closes up the door aperture to help prevent a car from getting to the driver. Matt Powers got mildly hurt a few years ago from the back of a car overiding his door bar and this could reduce the chances of that happening again. Matt got lucky and just got bruised and hurt his knee a little but it could have been worse. Darren McNamara broke his hand because of something similar as well. 
The side doors are just a skin for minimum weight.
