I am also experiencing the same thing. My ride is a 320, just 6 mths old. This has been happening over the last 2 months; problem is it always goes away and comes again another day. History is as follows:
1st time, heard loud metallic clanking sounds whilst menouvering in multi storey carpark. Everytime I either go up or down slope and turn, the very loud sound came on. Panicked and was gonna send the car to PML the next morning. However, the sound disappeared when I drove off.
After that, softer sounds kept coming on and off. Sometimes like something is loose and sometimes like spring recoil. Really fed-up because everytime I make up my mind to send to PML, the problem somehow disappears.
Can anyone help pls?