I have a pair (both left and right) of rear light/lamp covers for a mk5... although they may also fit mk3 and mk.4...
to be honest I bought these over 5 years ago as part of plans for fairly major repairs to my mk5.... although once I received these in the mail, I never even opened them to look at them as I wasn't ready for them at the time, so I can't confirm their condition, although they were bought in very good condition, and I know that there are the plastic screw caps on 5 of the 6 screws on the rear of the units.
Since I have got rid of my mk.5 (almost 4 years back) I have no need for these... while im sure I could have sold these on ebay... I appreciate all the advice and assistance I have received from various members of this forum, and so I offer them free (that's £0.00) to anyone that can pick them up (or have them collected by courier)... I may be able to Post, however I do not know what it would cost (and I would have to ask you to pay the postage)
I live around the Glasgow area, PM me if your interested, or have further questions.