Umm...as it turns out, the one in my link looks alot like the Scosche harness that I've seen mentioned here:
...but I'm not entirely sure they're one and the same as the link I posted doesn't mention the Scosche name or that part number. They do, however, show the website they come from:
...so I took a look at their site, navigated my way through to the 2004 Bonnie audio install parts, and what do I find but this:
Pontiac BONNEVILLE 04 2004 Car Radio Wire Harness for wiring new Stereo
Dig the write-up.....and then dig the price: $9.99
Whoa!....is that right? 10 bucks for this one versus 100 bucks for the first one I posted about versus 120 bucks for the Scosche harness. Seems like a no-brainer, price-wise...but you know what they say about things being too good to be true so that'* why I came here seeking the wisdom of those who hopefully know better from experience.