I have spent more time than anyone, I would guess, driving around in my Coupes (30,000 miles & 8,000 miles) systematically isolating the guilty parts to the point where I had NOTHING in the rear half of the car. Here is what I have learned:

Go to your dealer and ask for a LONG strip of window mounting tape (sticky, rubber-tar substance). You might also get a can of silicone spray lube.

Here we go:

- Chassis flex brings out the worst in these cars. The hatch area is rife with poorly designed butt-joints and plastic fasteners. You are going to have to remove everything, especially the corner mounts where the retracatable slide cover locks in.

What you have to do is eliminate the parts' ability to generate noise when the move and rub (which you cannot stop from happening). You can't stop them from playing, but you can take away their guitar strings :-) "Pad" contact points with generous, but not excessive, pieces of the window tape/putty.

This will take you some time, and you may want to test things as you go along. If your cases are anything like mine, your "issues" get worse in colder, damper weather. Stands to reason. Do your work on a shitty day for maximum satisfaction.

Other problem areas of note:

- The inside cover of the B pillar (where your seat belt guide is mounted) is a very tight, plastic on plastic joint that makes loud cracking kinds of sounds now and then. THis was a very cheap design by BMW. I have not yet engineered a solution, but am confident that when I have the time to remove that whole section it can be cut down a hair and the pressue on the joint relieved.

- The glove box is prone to squeak and vibrating if you don't have anything in it. Silicone lube and / or keep a couple large caliber handguns in it.

- On my car, the center console where the radio and guages are, everything seems "loose" and squeaks a bit if I bump my right knee up against it. It even lets out a little creak when I make a hard shift into 5th! I think I will spray lube the plastic joints and see if that helps.

All in all, the M Coupe is a great driving car and the coolest looking thing on the road. BUT, I think it is poorly made and has disappointed me as a BMW owner. Dare I suggest that this has anything to do with it's being made in the USA? I don't know.

Good luck, fellow squeak hunters...