my suggestion is that you contact them directly. when i put in my blitz TT there was a white wire that had no where to get hooked up to and it bugged me out so i called up blitz and they told me it wasn't needed. basically all you are doing though is breaking the ignition wires ( theres a blue, 4 wire connector under the dash to the right of the steering wheel if you have a harness to use), running them into the TT and then out of the TT back to the wires you just cut. kinda like cut and paste, if that makes sense. my guess is that not much has changed as far as ignition wiring goes between model years... im sure a 99 needed to start just the same as a 05.
the reason you dont actually need one is because IHI turbos are water cooled as well as oil cooled. when the ignition is shut off water is still circulating through the turbo via that coolant resivior that is to the left of the intercooler.