[BDO]

My 2016 X6 (120k km) has developed a "clack" which sounds like it's coming from the tailgate, and sometimes from the front passenger door, usually when driving over a speedbump, but also sometimes when braking.

I've done numerous searches of this and other sites, and have tried the fixes of wrapping the tailgate latch with electrical tape, as well as the plastic stops on the car and the tailgate. Hasn't had any effect. I've also looked for any loose items in the storage area, to no avail.

I'm not the DIY type past the above, so took the car to my mechie, took him for a drive and he heard the noise. He advised that the cause would be difficult to pinpoint, he can't guarantee that he would find it, and it may introduce new rattles in the process. He say it's not a mechanical issue.

I'm looking for any advice on what I could do to locate and solve this, as I can't live with it and I don't want to sell a mechanically great car which has never given me any problems in the 4 years and 50k km of ownership.