PBT-GF20 is 20% glass filled PBT, it's just a material callout. There's probably another small number (1 or 2 digits) on there somewhere that will be a mold cavity number, because all of that stuff is done in multi-cavity molds during injection molding. That's not an important number either, so ignore that one as well.
What's the front of the connector look like? Are the connector pins rotated 90 degrees from standard, and are the mating contacts flat or square? If those are rotated contacts (which it appears they are), that narrows down the possible connector families by a large amount.
I haven't seen a Delphi connector with that style of double lock plate (the red part), that's a new one for me...