I don't know why it's so far-fetched at all. There are Legacy's with the 2.5 that trap 107-109 mph with only a full exhaust and ECU tune -- *nothing else*. I know the WRX gets a different turbo but still, the 2.5 makes it a completely different car than it was with the 2.0.
I also know about being forced to sell your car. I sold my Stealth because I got caught hammering some guy in a stock LS1 SS from a redlight. I had pulled him easily from 60-120 and he actually thought he'd fare better from the redlight. Right in the middle of nailing a great lauch, I saw 3 sheriff's cars on the side of a convienence store where they were finishing up a report. I'm better off without the car now -- nobody instigates runs with a sleeper, and it'll soon be much faster than the old car was