the engine code isnt too difficult. for the 3.2 coupe base/limited the engine is the same as the R170 MODEL MERCEDES 320SLK. Now finding performance parts for the engine IS the difficult bit!! K & N filters or custom intakes like the TVT Designs, Needswings ones (you will find info on this forum) change the exhaust pipe and get a chip upgrade (INMOTION etc) and a sprint booster to lose the pedal lag. not much more you can do after that except add some NOS maybe or if all else fails get an SRT-6!

I think it is the M112 ENGINE