So the uav option includes the 6.5" pop up screen obviously, what about the u2s option? It also includes the 40 gig h.d. and 5.1 surround. Does it also come with a 6.5 " pop up screen for an interface -nav, or is there no pop up? What about the standard optioned car for that matter..they all seem to have the cutout for the screen. I'm assuming only nav equipped cars get the cool screen, right?

Only UAV cars get the 8" pop-up, U2S cars get the same dashboard, just no screen. I am not sure that U2S comes with a 40 gb HDD either.

no screen unless you pay up for NAV....

Thanks, thats what I thought. It's a necessity for this car, I think I'd really regret not having that. Am I the only one that has a difficult time figuring out the damn option list? Ordering my 07 corvette was much easier, The cadillac options include/exclude things with no explanation.

Did you see something that says U2S comes with a hard drive?
I haven't messed with enough to know.
The U2S is usually the uplevel base radio, which would mean no popup screen but more options than U2R.

On edmunds and cadillac sites u2s reads identical to uav down to line about the nav. There is no mention of the 8" screen in either entry.

When I first ordered my CTS I went with U2S but quickly changed the order to UAV and I am glad I did. U2S does have the hard drive and it actually has more free space on the drive since the Nav files take up most of the hard drive. The screen on the U2S is fixed and small (compared to UAV) but it does provide most of the audio capability of the UAV except no navigation and no pop up screen. The screen (which is monochrome) looks similar to the UAV screen in the down position but U2S uses buttons on the ledge at the bottom of the screen instead of being a touch screen. The Bose 5.1 amplifiers/speakers are identical for both systems.

I guess another question from someone completely confused by Cadillac's option list. Is it possible to get just the nav option on the Base Caddy. The caddy website seems to suggest that to get the Nav I have to get the Seat package. However My budget only allws me to get the base car. However I might be able to spring extra for the Nav (at about $3000). So is that possible?
Is the nav a standalone option on the base car. (and I mean base base manual, 3.6 non DI with leatherette interior (Which BTW is a million times better than my Mazda Leather)

Based on what I have seen over the years, I wouldn't be surprised to learn that the nav is only available with higher trim level options.
You can try going to the www.gmbuypower.com website, which I guess now is www.gm.com/shop, and building one to see what kind of options limit the availability of nav.
There are usually other items that the nav uses that require more optional equipment to be installed.