I'm sure I've mentioned this before, but the show Top Gear has a test track that they put cars around, here are the most up to date lap times I could find...
Pagani Zonda F - 1.18.4
Maserati MC12 - 1.18.9
Ferrari F60 Enzo - 1.19.0
Ariel Atom - 1.19.5
Porsche Carerra GT - 1.19.8
Ascari KZ1 - 1.20.7
Mercedes McLaren SLR - 1.20.9
Ford GT - 1.21.9
Ferrari 360 CS - 1.22.3
Porsche GT3 RS - 1.22.3
Anyway, Williams put an F1 car around that track and went comfortably under a minute.