The new Porsche Cayman GT4 is one of the best performance car bargains of the last decade. It contains a lot of 911 GT3 technology and know-how, is powered by a fantastic new 4.0-litre flat six engine, and to drive, it is close to perfection. And all for a mere £75 grand. Right now it is in a class of one, and it’s hard to see that changing any time soon.