Clunking noise when roof opens and closes

[Epigram]

How noisy should the roof be when it opens and closes?
Apart from the dry whine from the electric jacks, mine occasionally makes a loud clunk as it starts to open or when it finishes closing and latches.
It does this even when there is nothing in the upper bed and with the mattress removed.
The clunk is usually from the rear. it seems as though something is catching because the roof jumps slightly, however I can’t see anything.
I mentioned this to Mercedes when it was having some other remedial work and was told that they had compared to their other vehicles in stock and “It was no different and OK”. Unfortunately, I didn’t have time to make a comparison myself and I am now on holiday.

Does anyone else have similar clunks and how has it been rectified?

 

[David Tsang]

Ours has a slight clunk but more at the front as the locking catches engage!

 

[Brian Drought]

It's just as the latch disengages, all fine. Sometimes it'll do it more if you're parked on a slope etc.

 

[Epigram]

Thanks for comments.
My clunks started after opening and closing several times on my dead level driveway. However, after few nights away, it’s now closing silently. For the moment.
Having looked at the mechanism more closely, I am surprised at the lack of lateral stiffness if you push the top of the roof sideways when open. This probably explains the susceptibility to uneven latching if the ground is not level.
The micro switches seem a bit delicate for something exposed to the elements, as do the electrical connections to them which do not have sleeving to protect them.
Still, I suppose Mercedes / Westfalia know what they are doing........ ;-)