I am getting a metallic buzzing from the dash area that seems to be related to the Revs on drive - clutch in still, still occurring. 

Seems to occur around 2000rpm, and  sounds like a buzz/vibration/rasping sound. 

Are there any heat shields or similar around the engine bay that could cause this perhaps?

I can ignore it for a bit but after a while, it just really grates on you. 

 

Any suggestions would be most welcome........

 

This was well documented on early Superbs that a pipe between behind the dashboard would buzz at a certain resonance. I test drove one that did just that.  

 

More info here:

 

 

Mine does it from time to time 2nd gear overrun been the worst culprit. 
 

Seems to depend on time of year, temperature and volume of stereo …

 

It doesn’t bother me anymore.