Uou would need to do 2 things to make this SC work in the celica...
1: needs a new manifold, if it had one made for the celica so it fits under the Hood
right, it would be all good. It'd work on the GTS as well, but you'd have to either lower the compression of the engine, or run a smaller pulley on the SC (less boost). You could also make a fiberglass or Carbon Fiber Hood
that accomidates the SC. Perhaps if you add a cowl to the Hood
2: Fuel management. it comes with an ecu that'll work with manual GT's, anything else, you'll need to reprogram the ECU, that includes all GTS.
The Blitz also only works w/manual tranny cars too. (Auto & Manual use different ECU's)
Give toyota some time, they're working on it.
not impossibe, just tricky.