Hi Chris,
That's pretty scary after just a few days.. Good to hear the tracker did it's job and car was recovered!
The STi/WRX thing, And impreza is an impreza to theives.. They are either stripped for parts or used as getaway card for other crimes.. It possibly attracted attention because it was a "new kid on the block" as it were. New car, so possibly kays are at hand in the house.. This is the problem with the modern alarm systems, their not so easy to bypass and the best way is just to get the keys
As for protection against this sort of thing.. Hiding keys a good plan, in this case they still foudn them.. But alternative coudl have been you were in the house when they broken in and threatened youa nd your family for the keys.. So really best situation is not to be anywhere near them! (or get a BIG dog)
In terms of security, the only thing I've come across which may help is cliffords backjax system. In this case they could still have drivin away with teh car but after a mile or so the car would shutdown and send you a text so say the car has been nicked with GPS co-ordinates to say where it is located. The idea is the theives think they get away with the car but then disables itself a safe distance away. THe inconvenience with this system is that you need to rememeber to type in a code combination onto a subtle control pad ont eh dashboard (usually near fog light switch) every time you drive off.. Also whenever a door is opened the system re-arms. It's inconvenient to the owner but a decent security system.
Hope the police are able to catch the buggers who are responsible.. Car thefts are often a small part of much larger crimes brewing.