Rumble/Vibration from the nearside(I think)

My wife's fabia seems to of developed a slight rumble/vibration which seems to be coming from the passenger side.  It mainly occurs when accelerating from low revs ie when changing gears.

The car has recently had a MOT which it went straight through even though I thought it would fail on the hand brake being to high and whatever is causing the vibration.

I am not sure what it could be, any suggestions on what it could be , gearbox, drive shaft ???

The vibration doesn't seem to effect the performance of the car.  The car is a 1.2 2004 model.

Thanks