my 52 plate Octavia has a symphony HU, cassette deck with 6 CD changer in the boot

I've seen various things that may or may not enable me to add an additional auxiliary input. Does anyone have any experience of doing this? Please note I'm a car stereo novice when it comes to fitting them!

What I've gathered so far is that any aux input would have to share teh cd changer input connections

I've seen two possible solutions

1)Auxiliary input converter

..looks like you can by audi and vw versions, but I cannot see any skoda specific ones and additionally they do not seem to indicate that the cd changer and auxillary input can be connected at the same time

2) http://www.k9spud.com/vwcdpic/ - but I can't see anywhere to buy this any more!

there seem to be different Symphony HUs around, but the manual I have is rubbish. No tech stuff in it at all and nothing about connections on the rear of he unit

NB: I did try a cassette adapter for a while which was OK until the cassette player decided to twist round the cable going into the cassetter interface! For a mo thought I totally knackered the cassette deck, but having had to snap the cable to get it out, it seems to be OK.

Any help greatly appreciated!

sorry I posted this in the wrong place!