Hahahahaha! I just found that last week while stripping the interior and was wondering what the crap it went to...except mine didn't have that grey piece - it was just a white plug sticking out. I couldn't find a corresponding plug for it, but this explains why
. I CAN tell you though that the green / yellow tracer is only hot with the key in the START position, and the green wire is hot all time. (At least with key on ACC, not sure if it's hot with key off)