If there's a "secret" launch mode in here, I couldn't find it. In fact, the S5 punishes pedal overlap. Best run was in Drive with "Whack-and-go" technique. Upshifts are amazingly quick and seamless. Linear power delivery throughout rev range and gobs of gut-flattening torque. The V8 sounds better, but is no quicker/faster.
Typically impressive S5 brakes -- firm, fade-free and powerful from first to last stop.
Skid pad: Makes good grip but has awful balance. Understeer, understeer and more understeer...regardless of what one does with the throttle and steering. Slalom: Solid and unflappable but not as impressively responsive as the sedan with Driver Select package. Can feel compromise in stiffness in this test.