from CarandDriver
" Toyota once again handled the design, while engineering and construction are Subaru's end of the deal. The sports car's chassis carried over, but some new materials and adhesives taken from Subaru's Global Platform have increased the rigidity of its front end by 60 percent. "
Their exhaust looks like it comes from this Chinese ebay catback
https://www.garagewhifbitz.co.uk/news/new-product-whifbitz-supra-a90-exhaust-range/
https://www.ebay.com/itm/TITANIUM-EXHAUST-CATBACK-MUFFLER-for-TOYOTA-SUPRA-A90-2019-3-0T/284014820781?hash=item42209a3dad:g:IBoAAOSw2S1fY0t~
They're a bit pricey but definitely unique and having the built in fix is actually pretty sweet.
https://www.evasivemotorsports.com/store/product/evs-tuning-carbon-gtlm-aero-mirrors-toyota-gr-supra-a90-2020/