Hey Guys,
I was talking to a German friend of mine who owns a 1M. He had changed out his exhaust system and sold his OE system. So he sold it. The guy who bought his mid pipes with cats - cut open the rear resonator in order to quell the "drone" that everyone hates. When he cut open the resonator at the end of the mid pipe... he found out the resonator dampner was DUMMY! Inside the pipe, was a solid pipe and passed thru the "resonator"!
So... this might be of help to someone wanting to rid their car of the drone. It should be noted that some 1M owners have insulated the area around the BlueTooth box under the trunk carpet where it meets the rear fold down seat area. You could use some DynaMat to try it as a fix.
But I think the news that the OE mid pipe is a "dummy" is quite interesting!
the resonator at the end of the mid pipe...
UPDATE...
I think I found a pic(s) of the factory 1M mid pipe resonator cut open. Like my German buddy told me... he sold his OE 1M mid pipe to a guy wanting a louder exhaust... so he cut open the resonator and was going to make a "straight pipe". But to his surprise... THAT is exactly what BMW had already done! So now we know why the stock exhaust drones a little bit!
Here are the pics I found on the web...
