I'll pass on 90+% of these changes as well. Amusing to hear that he says that it's going back to get truly pimped out soon.
Love to see what can be done though. If I were so inclined I would go with another seat entirely (and lose the pattern), although I'm sure the options are limited, as the space is a cramped one. I would also stick with a continuity of surfaces (either all CF, all brushed aluminum, all chrome, etc.) as the mixture is not to my taste.
Since it exceeds the Roadsters accessory 12V current rating, the sound system required a separate 12V supply which has to be charged (again separately) via that plug under the rear diffuser. The video shows the sealed lead acid battery where the stock subwoofer would be and the 120VAC to 12VDC inverter mounted behind the rear grill.