At leat acording to Autocar today That accolade went to the Mazda MX5. I note the following lap times around Rockingham race circuit, though:
Pagani Zonda: 1:22.7
Impreza STI Spec C: 1:22.8
EVO VIII FQ300: 1:23.4
Having briefly tried that particular Spec C, I can confirm it's exceptional performance!