2002 Audi TT head unit swap. Need help
 

Hello all, just bit off a bit more than I can chew.
I have a 2002 Audi TT with a Concert Stereo (can't find a back picture of it) that I'm attempting to swap out for a Pioneer DEH-7300BT (back shown with wiring). A little over my head. I think I'm missing a wiring harness but I'm not sure what I need to get. I've been looking at this AUDI TT 02-05 Radio Stereo Install Dash Kit + wire harness + antenna adapter | eBay but I'm not sure if it will work. The Pioneer fits perfectly in the slot and the cover can close so I'm happy about that. If anyone could provide some insight on this it would help me a lot.