My V6 has about 23k km on the clock,fairly new and quite stiff,methinks it was a demo

I need to know if fitting a stainless steel exhaust will improve the efficiency of the motor, OR, how would I get maximum efficiency out of my beast (I look for an excuse to take it out more than once a week,wife thinks I got a skelm,does not believe I just want to drive the Paj

A long range tank?? Any wise words?
I've got a neat compressor,anyone mounted one in the engine bay? Is it worth it?
Anything else that I can benefit from on the Gen 4 side??
My first Paj,hopefully will last longer than I will!
Thanks in advance!
Cas