Because I was doing the same search 3 years ago, spent 8 months looking and then went a bought a blob spec c instead. If it wasn't quartered (which I can't actually remember a car that wasn't), it was heavy hit in the front. At the time, a mate told me he had done the same search 4 years prior to me and couldn't find one either, and the general state of them isn't improving generally. Thats not to say you wont be lucky and find a unicorn but if you do, the seller would want to be off the rocker if the were selling it for reasonable money.
Bring a paint gauge with you when you go view them and check the quarters first, pull out the trim form inside the boot and look down the seam for rust because after they've been hit once, unless they are repaired 100%, they can get rusty fierce quick. On the front, check it the wings have been painted,99% of the time, the bit around the bolts which would effectively be inside the engine bay will be body coloured which it shouldnt be.
I would search concurrently and if a mint blob STi comes up, then jump on it would be my advice.