2022 Porsche 718 Cayman GT4RS review! The Porsche Cayman GT4RS is the ultimate Cayman, and the ultimate mid-engine Porsche -- a GT3 engine in the Cayman! Today I'm going to take you on a full tour of the GT4RS to show you all the quirks and features of this special performance car -- and I'll show you everything you need to know about the GT4RS.