08 cadillac cts

[D*****T]

Hello and I am new to the forum. I am trying to install the pac nu cts2 on my 08 cadillac cts and I am now lost. I am at the point of locating the VSS wire in the gray 20 pin harness. Then the instructions say to cut the VSS wire and connect the green/black wire from the pac unit to the radio/plug side of the VSS wire and the green/white from the pac unit to the v we hive side of the VSS wire. I really need to know what color is the VSS wire and how to hook this thing up to the radio and vehicle side. I have read where several people has hooked this pac nu cts2 unit up and if you could help me out I would really appreciate it. My email is dtheus@charter.net.