2012 Multivan T5 has weird sound from front floor?

[archimylife1279]

Hi all,

Recently I notice that there is a weird sound comes from floor of both driver's and passenger's sides. It comes with a light vibration and usually happens when accelerating immediately after gears switch especially when switching to D3, D4, D5 and D6 gear. I have sound recorded and it can be found in the links below
YouTube
at the 41 second place and
YouTube
at 1:03, 1:23, 2:12 and 3:27 places
hope these two records make my question clear.

My car is a VW 2012 T5 Multivan

Any reply is much appreciated as that sound is really annoying.

Cheers