What is the best way to modify the exhaust on a BMW M3?

I just bought a BMW M3 and I want to make it sound better. Should I install a cat-back exhaust or go with a full exhaust system? Will it affect the performance of my car? Any recommendations?

Congrats on your new BMW M3, it's a great car! In terms of modifying the exhaust, both a cat-back exhaust and a full exhaust system can improve the sound of your car.

However, a full exhaust system will also increase the performance of your car, as it allows for better air flow. If you want a more powerful and aggressive sound, go for the full exhaust system.