Bartman

Im fitting a pioneer radio to my 2006 a3 sline and it didnt work on examination i pulled out connections and delved futher into cables and found wires all over the place white connected to yellow ,black soldered to brown etc (a complete rats nest) any one got any info on proper wire connections or any advice where to get futher info . Or if i could get a picture of the connections from dash side of brown and black connecters going to radio