DMCroww

Okay, I know, I know. It probably is here somewhere already and I found some tips but there's so many things about this and my head already hurts from searching.

So to the point.
I am having trouble to understand what to do to have an AUX input in my 2000 TT with OEM headunit. The problem I'm having is that my CD changer wont read the discs. I bought the car, found some old audio CD's that I knew are working but it was showing "ERR" every time... so no bueno. I read on some posts here that there is a way for hard-wiring an AUX cable to trick the headunit but as I read - the CD changer has to work.
I searched the internet for many days now but I feel like I'm still at the start. Found this on the amazon ( ) but I just simply don't understand how to do it and i don't want to waste my money. I have my "Cassette to AUX" converter but it has just too much noise in the background in between the songs and also there's the 'clicky' noise coming from the headunit. I'm sort of an audiophile so this bothers me. I also found some units that are supposed to plug in and work as an AUX input when the headunit is in CD mode but those require working CD unit AND are no longer available.

TLDR:
I want to have AUX input with the OEM headunit. No CD changer required, low cost.
If anyone knows how to do it or can point me to the right direction, I would be thankful.

Main requirements:
OEM headunit
No soldering or wiring - just simple 'plug-n-play' stuff
CD changer can be removed