I have had problem with the noise from the back since I bought the car (2003 model). Last week I went the the BMW dealer and ordered the small rubber bump that has been described in the previuos post. BMW charged 5 sek for it (less than a dollar). It really helped! The noise is all gone now! Finally! You have to close the hatch a bit harder to make it close properly after I installed it, but it is worth it. My car did not have any rubber stops next to the hatch locking previously. Thanks all of you who posted this info, without that I would never been able to explain to the BMW dealer what the problem was (as they had no idea).