I tought it was louder because of a gasket on the exhaust part which we have changed... but last week I was obliged to use my car to go to work.
I have some hearing problems, but when I drove the car last time, I was sure the sounds was louder not under the engine (in front of me in fact) but behind me. Before to go to work, I let my car to warm, and I decide to take a look under the car, on the rear.
This is what I found :

The pipe before the backbox is broken... :evil:
So.. I've order a new one..
Then, last sunday I met a 323F V6 owner :

I drove his V6 and it's amazing !