Yes, it sucks, but fortunately SVX make up less than 1% of the vehicles in your area and should be much easier to track down.

Ebay was a great suggestion. Also check the following and you will either a) get your car back b) catch that ******.

1) Check with ALL the surrounding Subaru Dealerships and window repair shops in search for an order for a SVX window and SVX keys/ignition units. I'm guessing that would require proof of insurance, finance, or title to so so. Chances are, if they are going to keep it to drive they will repair it and (which brings us to #2)..
2) Check with local paint shops. More than likely they will try and give the car a cheap paintjob to quickly change the color.
3) Also check with junk yards for your car. They might try and sell it for quick cash.
4) If they sell to a private party and you have filled out a report with the correct VIN #, it should be flagged and they won't be able to get insurance.
5) I'm guessing it won't end up in a used car lot b/c they won't have keys or a title!

Be sure to offer money for solid information, like $50-100 cash, and be very nice to every one you talk with. Give them an incentive to call you back. Buy a notepad and write down all the places you've called, times you've called, people you've spoken with, and any leads... it will be nice to have it all together.

Good luck.