The owner before me had done a so-so job at fixing a broken hose. I was tired of looking at it and I knew it was just a matter of time before it would leak fumes through small cracks (probably was already).
So I bought a new set, both top part and the actual hose (for 8V only i reckon):
http://www.amazon.co.uk/GOLF-VENTO-BREATHER-037103213B-C711/dp/B006Q9FY3C/ref=sr_1_2?ie=UTF8&qid=1362675755&sr=8-2http://www.amazon.co.uk/GOLF-VENTO-2-0L-BREATHER-493AK/dp/B006P37QEO/ref=sr_1_1?ie=UTF8&qid=1362675755&sr=8-1This was the attempted fix (weren't apart though):

This is what the insides of the old hoses looked like:


Anyway so I guess this a strong recommendation to anyone who hasn't changed their breather hose from the factory-equipped one yet... nasty as hell, can't be good for the engine. at least clean it, if your hose isn't broken.
If your hose is broken, here's a few tips on changing it:
Removal of the hoses is very simple. The one attached to the engine block (?) is removed by pulling the clip holding it up. Save the o-ring on the hose when you take it off (you can clean this and use it for the new hose - it's required to get a tight fit).
The top hose is best removed by unscrewing the two screws in the black cover box. With this done, remove the hose from the air intake (just pull, nothing will break) and remove the two other ends also. When putting the new one one, turn the black box 90 degrees, so you can easily attach the new hose. Turn it back and attach to air intake again (remember to screw tight again)!. The two hoses attach fairly easily. They could use another cm in length, as they almost seem too short - if you're worried, tighten the connection with a jubilee clip.
Done:

Cheers.