The work has been done by SpeedKore, and the company VP, David Salvaggio, visits Jay to talk about the conversion work and the methods of getting the carbon just the way they want it. The demonstration car has been left unpainted to show off the weave and the attention to detail, and while Salvaggio doesn't mention the exact amount of weight saved, he name-drops the Challenger Hellcat they managed to lighten by 650 pounds, even if that work included removing the rear seat among other modifications.
What he does mention is the cost to switch to carbon panels - and that's about $70K on top of the GT350R purchase price. Separate panels such as the immensely light 1.8-pound front wing are about double the price of the original component, at cheapest. But as the technology progresses, the cost of carbon fiber is bound to come down, and Salvaggio is adamant OEMs are pushing carbon forward to be able to produce lighter, more efficient cars.
A muscle car such as the GT350R definitely benefits from lightening, and replacing the steel roof panel brings the center of gravity lower. Salvaggio also says that since the panels are now bonded to the steel chassis instead of spot welding, there are structural benefits, too. Jay seems suitably impressed, and so are we.