It's not maxed out until he's running 285 or 315 width stickies... on 16 pound 18x11s with $8000 tripple adjsutable shocks and 9 sets of springs in the garage and has replaced every legal component in the car for weight reduction and pulled his AC and ABs systems and stripped the paint and resprayed it with 2 coats for weight reduction and rebuilt the engine from the ground up and cryotreated his gears and installed a ridiculous standalone ECU with 6 different race gas maps and anti-lag and tried 7 different intercoolers and... well, you get the idea.
Put it this way... Scott has maybe spent enough money to cover the budget for the absolute hands-down fastest possible ESP WRX.
However, for a realistic amateur autocrosser with a real-life budget that drives his car frequently on the street, he's pretty much done what he can. It's gonna be a good car for sure.