Bought the car yesterday.
It has some minor issues, but overall is in great shape. Car is at the dealership now getting some of those items looked at.
Paid $14,600. Might have overpaid a bit, but the chances of me finding another red on red close by in good condition are pretty close to zero.
It does NOT have any tune. Seller was obviously confused...dealership told him it had been "updated" to the latest software - he thought that meant it had been "upgraded". I will probably add the GMPP tune to it in a while.
Has a pretty annoying rattle/squeak somewhere in driver's door - hope the dealer can find it.
Runs nice and strong. Drove top down almost 5 hours at 80mph to get it home. Of course, I'm a little sunburned now, but still have a big permagrin!
Will post pictures when I get it back from the dealership and all cleaned up.
Thanks to all who provided help/info, and special thanks to ChopTop for finding it in the first place.