Anyone here familiar with the installation of a GTA Carkit bluetooth setup?

Long story short, I installed one of these in my 2006 GS430. Worked like a champ. Disconnect a plug at the back of the CD changer unit, plug in the y-harness and the GTA module and all went smoothly.

Fast forward to installing the same kit in my friend's 2007 LS460.
When I installed the kit for him (the same exact way I installed the kit for my 2006 GS430) the module's LED would not light up and the kit would not function. I connected the module both ways, directly to what I think is the CD changer port at the back of the head unit (which didn't work) and then using the supplied y-harness, and neither even lit up the module. Even more strangely, disconnecting the plug at the back of the radio unit that matched the plug on the GTA y-harness did not even stop the CD changer from playing music through the vehicle. What gives here?

Did we receive the wrong kit? What could explain this?

I used the port circled in blue below.