This will get you thinking
If i drive really quick, foot flat to the floor in Sport mode so its changing at the red line for a few miles and off a few roundabouts the exhaust becomes incredibly loud when i slow down and drive at ..say..40mph in 5th or 6th. Resonates through the car and booms. wind the window down and its really loud outside too :-)
After about ten miles it quietens down again and goes back to std. sort of noise. I thought it was just blowing the baffles out and after a while they choked up again. A bit of a long shot i agree.
Today i did the fast bit and then slowed down, exhaust really loud again but this time i switched off for a hour. when i re start, exhaust really quiet again.
The only thing i can think is its heat related. It didn't do this with the std back box but does it every time with the Remus back box.
When its loud you can speed up to 50-60 and it goes quiet again...
Any thoughts.?? its really embarasing when its loud, especially in the town !!spoils the car.
Oh..3.2 by the way