The top-of-the-heap niche within the mid-size (E-segment) super sports luxury sedans of the recent past and present is the domain of boosted V8s boasting north of 500 hp. That would be the the previous-generation Jaguar XFR. Approach the 550 hp barrier, and the last-gen Jag XFR-S is there. Break through to 560 hp? Audi’s RS6 […]