Mods on cars are as follows.
EVO:
-ASI race radiator
-ARC airbox
-Crappy JDM 3" muffler (baffling collapsed and packing clogged it up :S
-some sort of lowering springs
-Chargespeed EXT front lip
-O.Z. Route rally wheels (original rally gravel stage wheels, and no curb rash

)
-Evo III drivers seat (complete with Rally Spec. duct tape to cover the rips in the bolsters)
-Stock boost (10-11ish psi) (not really sure as i only have a light that turns on on the instrument cluster when in boost) stock boost is .7 bar... so thats like 10-11 psi.
GT4 RC Celica...
-Tien full adjustble coilovers/shocks
-Cat delete + full 3" exhuast
-O.Z. Route wheels
-Chipped ECU
-Running around 12-14 psi of boost.
Other then that its pretty much stock hes planning on getting a boost controller, custom intake piping with BOV recirculated and putting in some bigger injectors, a better turbo and then re-tuning it for higher boost.
Oh and a ASI aluminum race rad as well to go along with the increased heat.
We did some highway pulls and also from a dig and the evo pulled on the GT4 RC pretty good. I thought the RC would have its way with the evo... turns out the GT4 RC is short about 20 HP on the evo and weighs a shit load more. The RC is definalty a more solidly built car tho. Definalty not as light and agile as the 2750 lb evo tho.