Sound improvement Sl 500, year 2002, R 230

Hello, just bought a SL 500, R230, year 2002. What possibilities are there to improve the V8 sound – cheap -? Car should not sound loud, but sonorous, powerful, dull. Have read about replacing the center silencers with stainless steel tubes. Where can you buy something like this, what does it cost about and how are the experiences with it? Thank you for a few tips.