2007 m45 exhaust problem - y-pipe?

[AZ_m45]

Hi everybody,

This is related to the thread at: zerothread?id=220421

I was wondering if there is anyone out there who has successfully had their y-pipe replaced under warranty because of a rattle sound and/or cracking issue?

I have a late model (2007 with 32k miles) m45 that is making exactly the sound described by others, and the dealer says they will not fix it because the cats and exhaust heat shields are scraped up and have signs of "road damage."

The problem (for those not familiar with the previous thread): at about 2,300-2,500 rpm, the car intermittently makes a metallic rattling sound (like putting a coffee can of coins on top of a running clothes dryer). Many people say it's because of cracking or a design flaw in the y-pipe.

It frustrating that even though this seems to be a documented issue, the dealership is refusing to fix it based on the cats being scraped up from what looks like speed bump contact. The cats aren't even the source of the issue, and what car doesn't have scrapes on its undercarriage after 30,000 miles?

Can anyone offer feedback on this issue? Thanks in advance -- this is a great resource on the web for M owners!