Watched that race, the STi just seems like a midget among giants. The lap time difference during the race was pretty huge but I'm sure not having any brakes was the majority of the reason.
Does anyone know if the ESX STi is still running the AWD system or is that car now a RWD? What motor are the Porsche's running? NA or turbo? It seems that if the Porsche's can be somewhat competitive then the STi should stand a chance too.
What rules does the Speed GT series have about homologation? Do the cars have to come from a car lot and be built or can they be factory prepped race cars?
It seems you could buy one of the almost turn-key Prodrive Impreza WRC S10 cars and set it up for street and you'd have a pretty competitve package... semi-auto trans and all the bells and whistles.
http://www.prodrive.com/default2.asp?M=368