Mine has done this today, the noise is crazy

Hovercraft is a good description!!!
Today it done it at lunchtime, drove 5 miles back to work, stopped in the carpark and heard the LOUD noise over the music, opened the door and the full force of the noise hit me

Que getting funny looks from the guy in the car next to me
Got home tonight again after the 5 mile journey back, pulled up on the drive and my god the noise was there again!! This time opened the bonnet for a quick look around, but it didnt feel that hot in there - it wouldnt be having only travelled 5 miles @ 30mph! Stopped the car and eventually the noise went off, then started it again, and the noise comes back
Reading through this thread it seems lots do it, does this mean its normal?

Or is there a problem?
The car hasnt yet done 1000 miles, and hasnt done it before
....I seem to be spending too much time in faults and fixes lately
