Well couple of choices. I'd suggest running Yokohama A032R's if you plan on doing some track events. They will have the logest lifespan, offer consistent lap times compared to other race tires (Hoosiers), and still be sticky enough to keep up on the autox days. If you plan on doing more autoxing then track days I'd suggest the Kumho Ecsta V700's. They'll give you good life, great traction, and won't cost and arm and a leg.

With both of these tires you can install them in your garage the day before and drive to and from the track on them. Hell, you could probably get 8000+ street miles out of the Yoko's. I'd suggest 225/50/16's. I run Kumho Victoracers in that size and have slight rubbing issues when cornering hard, but nothing to be concerned about.

Yokohama A032R's are $165 a piece.

Kumho Ecsta V700's are $143 a piece (heat cycled).

These prices are from Tirerack so expect to pay a little more shipping.

2004 Focus PZEV 2.3L - KW sport suspension, SP camber plates, Eibach front swaybar, FS intake, FS Stealth exhaust, 3.82 Final, Torsen ATB, Prothane MM insert, E1 CSVT wheels 1/4 mile - 15.201@89.4mph