Yeah, I commute to Seattle every day for work, and haven't ehard of this - sources would be great...

... Yes

Results man, we want results![:D]

Well now...

Interesting info here..  If I hadn't trashed my bookmarks the last five or six times I recovered my system, I would have some more links to pass along..

A few notes and observations...

1) An SUV or truck is a better choice for armouring, due to the higher margin of weight "available" relative to the power and chassis of the vehicle.  Sedans and coupes will greatly benefit from the addition of power mods to the engine, or a new engine entirely...  Expect full armouring to mass several hundred pounds.

2) Make sure you do a COMPLETE job of arnmouring.  Don't neglect the engine bay and the fuel, and the underbody would be a good idea as well.  Best idea is to create a "box" for the pax, and a second "box" for the engine.  The fuel tank and underbody armour will likely be part of the box for pax protection.

3) Check what you replace your glass with, some varieties are sensitive to UVA and UVB radiation, and will need to be renewed at intervals.  Some other varieties do not need to be renewed.  Make sure you know the difference - old armourglass can actually become MORE fragile than regular glass, and even auto glass is a composite to make it shatter resistant...

4) Become familiar with the altered handling properties of your armoured vehicle.  Part of the reason for armouring the bottom of the vehicle is to offset the mass of armour elsewhere and keep the CG and roll centres low.  If possible, ballast in the cargo area will help to keep these loci as close to the ground as possible, and preserve handling characteristics (and may actually improve them!)

5) You will also need to relearn how to use your vehicle in a tactical situation, in the event it becomes necessary.  Also, you WILL want to take an E&E course in driving, as you will want to retain yourvehicle as much as possible in the event "IT" happens...  

6) One more point - Have "ports" in the armour, with covers that can be moved from the inside.  You may have a need to return fire, and you will not be able to do this from within an armoured box...

Hope this helps

FFZ

To those of you who think this is paranoid or unnecessary:
I have lived near the Seattle area for less than 2 years and I can think of at least 3 similar incidents.  The TKD champion, shot and killed at a red light.  A soldier on his way to base, shot and killed on the highway.  A woman shot at by a CCW holder because she "cut him off", on the highway.  She was not hit only cut by glass.  I'm certain the last one will be used as an excuse to do away with CCW's in this state.  I won't even get into the Mardi Gras riot, WTO riot(s!), Millennium Celebration, etc.
I have also lived in Miami and Houston.  There were many similar incidents in those cities when I lived there.
There was a rash of carjackings in Miami that killed dozens people in a few months.  Mostly German tourists.  Somehow the BG's could smell the German tourists.  The German government issued warnings to their citizens not to travel to or through Miami.  Only then did the city gov. and media take the killings seriously.  It's now illegal for car rental companies in Florida to put bumper stickers or other markings on their rental cars. This is why. Duh!
There was a cop that was shot and carjacked in his squad car in downtown Miami, a few blocks from the arena, where I was working.  Shot in the head, stripped naked and left in the middle of the street to die.  They stole everything, squad car, duty belt, uniform, etc.  Somehow he lived and later returned to work.  Giant Brass Balls!
In the aftermath of Hurricane Andrew my sister had to take cover behind her little Honda.  Some idiots started shooting at each other at point blank range with shotguns.  They were fighting about who was cutting in line to buy ice, $40 for an 8 lb. bag!  Cash only, and ATM's weren't working for months.
I was in an underground garage in NYC in '76? when the whole city lost power and fell into complete anarchy( I think it was '76, '77?).  Walking home during a riot that night is something I would only wish on osama and his family.
If you have never heard of anything like this in your area I suggest you start reading the newspaper or watching the nightly news.  Or you could just huddle with the rest of the flock of sheep and you'll probably be alright.  As long as the S never HTF in your area(i.e. LA riots, Cleveland riots, after earthquakes, hurricanes, tornadoes, etc).  Practice saying "Baah, Baah, Baah".
And in case you haven't noticed there seems to be a FEW people who would like to do us harm just because we are Americans.
Armor is not a guarantee but it will offer SOME protection against suicide bombers, rioters, looters, car thieves, crazy neighbors with a shovel, handguns and even rifles.
Mercedes, BMW and others now offer FACTORY armor with warranties, as an option.  You won't see them on the showroom floor but if you ask they have brochures and can order them.
There are a lot of custom car shops that will do this for you.  Mexico City has more of these shops than any other city in the world.  I wonder why?
Maybe those Mexicans are just a bunch of paranoid executives, testifying against the powers that be, with no sixth sense and some other reason to THINK they need that level of protection.  Say "baah".
"Just because your paranoid, doesn't mean their not out to get you".

I have not armored my car but I have thought about doing this.  I was told, by a guy at the auto glass store, that they occasionally order bullet proof lexan windows for people.  Its not a big deal to them.  Any auto glass shop should be able to order it for you.  Get the thickest that you can fit in your doors.  You will have to make a little modification to the frame.  If you can do this yourself you should be able to armor your car for a reasonable price.
For the doors and behind the back seat I would think that hardened plate steel would be best. It will give you the most protection for the money. Most metal shops can make custom steel safes and doors, same thing.  Have them make you the plates to the right size.  You can fit and install them yourself with standard tools( drill, grinder, propane torch and alumiloy rods)
Aircraft aluminum plates can also provide a lot of protection with a huge savings in weight.  Just not as much protection as steel of the same thickness.  More expensive to get the same level of protection as the steel.
Titanium would be nice, but how are you going to cut and shape it?  I think the labor and tools for this could quickly bust the bank.
Of course you will need those tires that will keep running after being punctured.  A lot cheaper than the real Kevlar lined, solid core "bulletproof tire".  But as long as your at it maybe you can get the real thing.
If you are successful you must post your results and pics here.

Sorry, but "Armorize" is not a word.  You can't just make up a word when one already exists for that usage.  Armor is a noun and a verb.  In this case you would say "Armor your car?"
Still would like to see pics though.

Titanium would be nice, but how are you going to cut and shape it? I think the labor and tools for this could quickly bust the bank.

Titanium is not much more difficult to work with than steel. I work with it at least once a week.

SKS, really.  Cool, then if Titanium can be had for a good price it definitely sounds like the way to go.  
That would be HOT!  Lexan windows, Titanium plated doors, solid core tires.
Where do we mount the mini-gun? Forward or rear facing? That is the question.

About $800 for a 4'X8' sheet of .050 titanium. And why not put the mini gun on a rotating turrent on top with remote controls in front of the passanger seat with a small video display attached to a camera that looks down the barrel of the minigun? ALL your friend would want to ride "minigun".