Well, this will teach me for assuming... I just bought a nice Alpine din-and-a-half head unit from eBay. I got it yesterday and I was surprised to find that the head in my STS is NOT a din-and-a-half! I haven't had a GM car in a while and I thought that they were all that size...
So, what size head unit do I need to look for? There are only a couple double din, non-screen head units and I'm not a big fan of the single din with cubbyhole kits...
Also, I've got the service manual and it _looks_ like I can add a non-Bose head by feeding signal-level tunes and power/ground to the Bose part of the harness, is that true?
So, the head unit (A perfect condition Alpine CDA-D852) goes back on eBay and the search continues...