I have the Invidia V3. It was on the car when I bought it, and was told by the previous owner that it rattled a little bit. After a couple months, the rattle started up again and has been present for months. Mainly right around 3,300rpm on accel and decel, worse when the car is cold. I have taken the exhaust off, and could not find anything. Did lots of searching and research, and the conclusion that i came to was it is something internal. Inside the muffler comes apart over time. I will be replacing my exhaust this week, with a brand new, non Invidia, so I am hopeful that it really is the exhaust that has been buzzing all this time. O yea, the buzz comes from the left side.

 

What are you doing with the old v3. If your selling it, let me know!

 

Yea it is for sale. The system really needs a little TLC, but I think it could look pretty good again. The rattle is there, but I have managed to ignore it for 8 months, so it is not a necessity for me to replace it. PM me your email address, I can send you some pictures.