I think I figured out what the plug is on the factory wiring harness.
It's made by TE Connectivity:
Plug - 2109441
Contact - 968857
Wire Seal - 828905
Empty hole plug- 828922
http://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Customer+Drawing%7F2109441%7FA2%7Fpdf%7FEnglish%7FENG_CD_2109441_A2.pdf%7F2-2109441-4