[el ess A]

That's the one that glues to the bottom of the glass, right? I've never run into that part number. It may be one of those parts made of unobtainium.

Also, I'm wondering if it's one of those things that comes pre-installed on the glass and isn't available separately? Just speculating. Only way to know for sure is to ask a glass shop or someone who's actually bought a GM back glass for a HT. They sure look like they're on there with more than just a peel and stick application. But I don't know.