I thought I'd start a separate thread for this topic, I think it falls under chassis modification:
http://www.bahrain.citymax.com/page/page/2625924.htm

http://www.aavi.com/crown-victoria.html

What is all the switches on the left of the steering wheel? Why are they different (I noticed the guage cluster)

Maybe WhiteFalcon or Omar would know, as it looks like that is a GCC Panther (note the wheels...)

The second photo is a 2001+ Lincoln Town Car. From the left, the first three switches are factory installed for panel dim, pedal adjust and TC off. I don't know about the four aftermarket switches though.

it looks as the just took a picture of a towncar interior...

It looks like a Cartier edition Town Car, so I don't think that's the factory armored version either. There is also some sort of control attached to the right side of the steering wheel just above the spoke. Also notice the straps to keep the front doors from opening too far.

Is the full-glass rear-door window (on the top link, the Crown Vic) something that is specific to GCC Crown Vics or is that an armoring modification?

I think they just used one larger piece of bullet proof glass instead of 2, on the rear doors.

I agree. The armored glass is a bit thick to have that little strip along it's edge, but that probably also means the rear windows no longer roll down (or at least not all the way), which was why Ford divided them. Otherwise the glass would hit the wheel well cutout.

The first car doesn't look to be a GCC spec because it has white walls, they never came in 16" wheels. The first photo looks like a 2002 Crown Vic that was armored. But nothings hints weather it is a GCC spec or not. Rear windows here are normal two piece.
As for the bottom pic, it looks like a 2003+ Town Car from the Gauges and the Center Cartier Clock. Also to be sure its a Towny and not a Vic with the interior changed, notice the rear door in the bottom picture, it has that body line that is specific to Town Car's body.
I personaly have no idea on armorod cars here.

The door sill plate says Linoln also.

Anyone recognize that steering wheel control. It reminds me of some of those aftermarket CD changer controllers, but I don't know for sure.

it reminds me of a lincoln towncar steering wheel

Our 2000 CVPI is lightly armoured, it has kevlar inserts in the doors and ballistic glass, we use it for secure transport.

We have a 2006 P71 on order right now, can't wait for it, it will only have the front 2 doors (from the factory) with kevlar insert, then the glass we will replace with a low ballistic value securtiy film (25mm or so of it). The 2000 is tired now with 140k kms on it.