To tell you the truth, owners are probably your best bet.

I've helped 2 now owners buy S2000's are they are over the moon with them.

Common traits to look out for:
gearbox clutch buzz
roof up any buffeting noise?
roof up any holes in the canvas?
mudguards / door hinges / bonnet / boot hinges - any evidence of rung off bolts?
door gaps - ar they equal?
service history completed and filed in the log book?
In the shade, any resprayed panels a slightly different colour?

Under the car is always good too. Check sway bar mounts, suspension components. Have the bolts ever been removed evident by rung off bolt heads?

Having said this, I'm sure any number of the WA / Perth based S2K owners would be more than happy to help you out and assist in an inspection / drive.