Nice find !!!
And two new details are revealed ... alcantara steering wheel and GTS exhaust ... but the car ist only an prototype. that shows only known parts from the GTS ... the car continue to hide its secrets ... the rest interior ist standard M3 and because all bodyparts are painted the intense of usage from carbon bodyparts are not visible ... until somebody knocks on bonnet, roof, trunk and door to hear if its plastic or metal.
I donīt also think for example that the production car would have the double hump dash with iDrive/Nav ... because of weightreduction reason ... I think A/C and Radio are the only electronical comfort intims ... also the production car would have to 100% some more sportier and lighter seats - if they come with alcantara or leather (as on the shown examples!) ... we have to wait and see.
Uli_HH