Just to pad this article out a bit,
if your window seems loose at the end furthest away from the door hinge, ie. you can lift it up and down by a small amount, then the loose bolt we tightened up is probably the culprit.
You have to first remove the door trim, there is a comprehensive guide here : http://www.bimmerfest.com/forums/showth ... ?p=2450085
**When you take the trim off watch what you do with the door locking rod as its a bit loose and can drop on the floor or get jammed when you shut the door**
Once you have the trim off (you don’t need to do anything with the airbag) you will find a moulded bit of foam covering the internals of the door. If you are only here to do the window rattle then you don’t need to take this foam sheet off.
Just below the airbag near the edge of the door you will be able to feel the hole.
slit opening with a sharp knife about 2 or 3 inches long directly over the hole.
In a minute we are going to switch the ignition on, before you do this make sure the car is on neutral, or park if you are a wuss with an auto box
its cheaper to do this before than realise it’s in gear as you crank the key one click too far!! As I store my bike at the back of the garage it would be even more expensive mistake.
The reason we have not touched the airbag is because we now need to switch the ignition back on to lower the window (if the airbag was unplugged and you switched on the ignition the airbag circuit does a self test, sees there is no response from the door bag and you would get an airbag light on the dashboard that then needs a dealer reset to cancel).
If you are doing the passenger side then you can use the driver’s door controls if not then you will have to plug the door card back in to use the control on it. Plug the switch in before you turn the ignition key, this way you are less likely to damage anything.
With the ignition switched on you can now lower the window. you need to shine a torch through the slit and peer through the hole, lower window until the head of the torx bolt lines up with the hole in the door, you will have wind the window down about half way'ish.
I lifted the window slightly and then tightened up the bolt, I was using a screwgriver and you can go fairly tight but if you are using a wrench don't strip it. I did think about unscrewing the bolt and putting a dab of thread lock on it... it's up to you, but if you do I don’t know what might fall into the bottom of the door when you remove the bolt... so be careful.
before you do anything else wind the window back up and (having made sure the other door on the other side of the car is open) shut the door. The window should now nudge up to seal the door against the soft top, it might do the same for the hard top but I am not sure. If in doubt check the other door and make sure it looks the same. Open the door again and give the window a good wiggle it should be a lot more secure now, if its not much better then you nigh have worn bushes too. Replacing the bushes is a bit more involved and you need to remove the bottom half of the foam in the same way we did in the photo above, and it's a bit beyond the scope of this quick fix.
But is the window is now working then let’s move on.
The way I would seal the hole is with some silicone sealant, the same type you seal baths with. I have been doing that for years with no problems. But to be honest you can leave the slit open and it really won’t cause any problems. In the drivers door on Sp3ctre's car the foam was ripped to shreds and full of holes (probably done by a main dealer!) so I siliconed the hell out of it. I generally then cover silicone with a bit of gaffa/duct tape this just stops the silicone sticking to the door card when you replace it.
And that’s it job done, as we had cut off the moulded foam took this opportunity to fit acoustic sheet in the doors, it can make quite a difference.