Out on the track we focus on the Complex, a tricky right-left-right called Campbell, Cobb and Segrave, respectively, that follows the pit straight and precedes a flat-out blast. Getting the corners right requires compromise: Enter Campbell too quickly, and you'll understeer wide, making a mess of the entry into Cobb.
To improve the Leon's athleticism, the R uses a new front sub-frame mounted to the chassis using Silentbloc bushings, a thinner (19mm) front anti-roll bar and quicker steering rack.
At the rear, increased spring and damper ratings are accompanied by Silentbloc mounts, which are designed to enhance the passive rear-wheel steering characteristics of the standard Cupra.
The mechanical systems are backed up by a stability system called Electronic Stability Program (ESP). There's no trick limited-slip diff like Ford uses in the new Focus RS. Instead, the Seat uses a traction control system with an Electronic Differential (EDS) to transfer the power to the road.
The changes are more than the sum of their parts. It's still necessary to use the throttle with finesse in first and second gear to avoid the tell-tale flicker of the tractioncontrol light, but once on the move, this car pulls cleanly and consistently.
And it's freakin' fast. Keep the engine between 2100 and 6000 rpm and the six-speed Seat can almost rival the Focus RS. In the corners, body roll is noticeable only by its absence, and the Seat is happy to hold a precise, consistent trajectory throughout the turn. This is a car that encourages fluency and precision, but, by turning off the ESP, it's easy to prompt the Leon into a glorious four-wheel drift.
There isn't much to complain about. The action of the aluminum brake pedal is too soft, and there's too much travel before there's any meaningful retardation. Once in action, though, the brakes prove impressively forceful. The steering could also do with more feel. The Leon turns in well enough, but it fails to communicate the minutiae of the grip levels.
Although we were never likely to threaten the lap record at Thruxton, we do leave knowing that the Cupra R is a more entertaining drive than the Honda Civic Type-R. This is a hell of an achievement for Seat, which has ambitions to become the Volkswagen Group's Alfa Romeo. It's also, we are promised, a sign of things to come from the marque, which can only be good news for any enthusiast. Except, of course, for those in America.