Officially, there are no performance cars currently in production in China, barring the 505 hp BYD Tang hybrid, if you care to consider it as a performance car. Another such contender is the upcoming BYD Song MAX hybrid.
Of course, the 1 MW Nio EP9 is a hypercar from a Chinese maker, but it has been produced largely in the UK, that too in extremely limited numbers.
From 2019, we might see a few more performance vehicles made in China from the likes of Saleen, Qiantu, Leap or even Lotus (Geely willing!) if these companies succeed in realizing their announced plans.
Cannot say if there are any enthusiasts developing/creating secret supercars in their garages as a private/personal endeavor.
Of course, the 1 MW Nio EP9 is a hypercar from a Chinese maker, but it has been produced largely in the UK, that too in extremely limited numbers.
From 2019, we might see a few more performance vehicles made in China from the likes of Saleen, Qiantu, Leap or even Lotus (Geely willing!) if these companies succeed in realizing their announced plans.
Cannot say if there are any enthusiasts developing/creating secret supercars in their garages as a private/personal endeavor.