Vibration / Knocking from the dash

[MingeBlue]

I got an 02 A3, I noticed that sometimes when I start the car the dash vibrates noisly, I also get a knocking sound front right of the dash when going over bumps. I managed to stop both noises by pushing a sock in between where the dash meets the front screen, though it doesnt look pretty and blocks the vents, anyone else had this and how did they fix it. I dont really want to get the whole dash out

Anyway wish I had found this site earlier, looks like Ive had most of the common A3 problems though at the time I thought it was just me

 

[guyl]

Mine has also developed an annoying rattle somewhere between the blower vents in the centre of the dash and the screen demister.

The aircon has also developed a 'clonk' somewhere deep in the dash that only happens within a couple of minutes of the car being started, this is then followed by a nice blast of cold (outside i presume) air around my shins.

Within a couple of minutes the aircon reverts to pumping out warm air as normal.

Any idea what the problem could be, or even a solution?
Thanks

(Sorry to hijack thread, but they seem similar problems!)