Is yours an early 98? or 99-00?
Is your PATS bypassed completly for some reason?? I know it's not absolutley full proof but you normally don't hear of SVT's getting outright stolen since they have the PATS security feature - the electronic code on the key has to match what the ECU has. You can't take a screwdriver to it or hotwire the car since PATS won't let you bypass it since it works off of radio frequences between the key, transponder and ECU.
They would of had to either have to have a copy of your key and program it or flatbed it out of there. If you had a 98 you would have to have only one working key - the 99 and 00 had to have two working keys...
Just wierd to me that that would happen to a PATS equipped vehicle. Then again if they had a programming tool and a key that worked - maybe - but why risk all that time?
Smart criminals.