1.2tsi.

I'm getting a weird high pitch (almost sounds like a scooter or moped on max chat - but quieter) when I rev through the gears or on on the way down when holding it in gear. It doesn't seem to be the engine itself? Or is it? Maybe there's some ****ty plastic/metal cover vibrating it's nuts off under there? Any ideas?

Is it at a particular rpm in each gear or is it at a particular speed in any gear?

Nope. Happens all the time above 2000rpm.