Jaguar XKR-S, the most powerful and fastest series production sports car Jaguar has ever built with a top speed of 300km/h FYI: Complete XKR-S Details Jaguar XKR-S Portimao, Portugal – June 28, 2011: Mike Cross, Jaguar’s Chief Engineer – Vehicle Integrity, takes us on an exhilarating run around one of Europe’s most thrilling race venues.