@khitran: You never noticed this before?
I was enjoying a ride with my friend in his week old 2006 Vario and because there was no other sound we noticed it. But in traffic or running engine it is impossible to notice. I wonder what that is and never asked him later if he found out the cause. But now his A/C is giving the smell of soiled socks, I think that is some moss or something but not sure if the two things are related.
Anyways people owning Varios themselves maybe more helpful.