Porsche engineers have been spotted testing a prototype for an updated version of the Cayenne Coupe. The Cayenne Coupe, as the name suggests, is a coupe-like version of the Cayenne designed to tackle high-end versions of the BMW X6 and Mercedes-Benz GLE Coupe, as well as the likes of the Lamborghini Urus, Aston Martin DBX, and upcoming Ferrari…