i found the info while going through a bunch of factory retrofit instructions, and in one of them, in the memo to the dealer mechanic, was this list of wiring harnesses that are already in the car, and the mechanic was supposed to use them.

Since there are gazillion variations on car equipment, I thought that the factory came up 5 main harnesses, to save on the cost and they probably groupped the most common options that go together in one harness... this way, they would have llimited the variations on the assembly line and kind of keep the cost down as well, as it is easier logistically to deal with 5 variations than with 2000 versions of main harness, and just eat the cost of the plugs and meters of wires that are not utilized...

I will try to dig up that retrofit instruction and see if i can post the actual page from the PDF file...

I thought the basic harness is the Level 1, and the most complex one is the level 5 - could it be the other way around - the simplest harness is the xenon lights, level 5 and the most complex is level 1, which was not even listed in the PDF file at all?..