Stelan,
You can do better than just make a noisy exhaust system ! It has been done anyway and it needs to be lighter and smog-compliant.
My vote is to create more reliability and power. Here is an idea I proposed and got no response to -initially.Rather like the AOS hack that became a pro-grade product !
An intelligent engine transplant kit - the Audi V6TT.The proof of concept has been done.It fits, it works.Here is a link with
all the photos . You and Ben should collaborate on this?
Porsche Boxster 986 - engine swap project - Page 1 - Readers' Cars - PistonHeads