TTP-Turbo Technik Pietz. This is a german tuner who is famous for his turbo kits for various car brands but I won't comment on the quality.
The body kit doesn't look bad but this is just Tuner work, it has nothing to do with a GT or GT3.
TTP offers now up to 450 HP in the Carrera S using a turbo kit aftermarket install. As far as I know, a lot of Gemaballa turbo kits were developped by TTP and even installed by TTP. Go figure...