You guys do have better fuel over there, but then again it probably gets pretty hot and humid.
As a reference, here are some graphs of the XT I had. Stock with panel filter and Prodrive 2.5" axleback:
VF43, STi TMIC and exhaust manifold, COBB catted downpipe and 2.5" Prodrive axleback (over-laid with previous graph, gains highlighted in yellow):
Same as before, but with EL header, Invidia 3" catted downpipe and 3" exhaust (over-laid with previous graph, gains highlighted in yellow):
Car made it to 80K at which point I put it back to stock and sold it. It wasn't a crazy fast car, but did pretty well (faster than E36 M3, probably as fast as an E46 M3 if not quicker off the line. Probably fairly close to 335i).
Stan