AUX in audio button help if compatible?

[ijavame]

Basically I have come across this aux in http://www.ebay.co.uk/itm/AUX-IN-AUDIO-IN-SWITCH-PLUG-CABLE-FOR-VW-GOLF-Volkswagen-5KD-035-724-5KD035724A-/190859587792?pt=UK_In_Car_Technology&hash=item2c701e30d0
 and I wish to know if it is compatible in a golf mk5 with a rns510 media system. Also if not how can I go about doing so as I really wish to install this mod. Thanks in advance

[mrxbox360]

Id also be intrested as im looking at adding http://www.ebay.co.uk/itm/310667109213?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 as iv got the blank fitted into my arm rest but i wanted to keep my cd changer,im wondering can the 3 wires be added into the excting cd plug or is my only option to use http://www.ebay.co.uk/itm/270998609237?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649.

Any help or advice would be a bog help.