Does anyone know if the STI gauge cluster would fit and work on an 02 WRX? and if the swap is all that difficult at all? thanks.

Yes it fits perfect the only thing you need to do is cut a wire ;"don't remember what cable but is yellow with a stipe i think is B22.
I already installed in my 02 WRX and also fit the mileage in www.tacomaspeedometer.com
is like $60.00

ps;is important to cut this wire if you don't cut the wire the radio fuse will blown.

I found the pdf instructions