broken cover on gear box?

[Mr.Tom]

On the top of the gearbox in my 2.0 mk3 is a large plastic looking round cover with a hex shape in it. It has been broken and looks like you can see into the gear box area. Should this be covered? What purpose does it serve? It looks like the hole in the middle is suppposed to be there, but perhaps a cover of some sort slots into the hex shape?
It wasn't mentioned when the garage were doing some work on the clutch cable that runs very close to it.
Just a bit worried that dirt can get in there and fudge something up.

[gtigolfthree]

Dont worry about that, it's the flywheel inspection thingy so you can see the timing marks with a timing light, should be a removable plastic bung thing probably be able to get one from scrappy.

[rubjonny]

main worry is if a bolt or something falls in there, or oil. new cap will be cheapy from vw

[Mr.Tom]

That's a relief then Will cover it for now.
Thanks.