An article for those who are in the market for a WRX in the future and are wondering about the Subaru Performance Tuning parts, and how it improves car performance: Tuner Cars - Subaru WRX SPT

All of the SPT modifications on our test car amounted to just over $2000, and though they don't do anything for the power-hungry, these simple adjustments go a long way to improve upon the already-good WRX and make the STI seem downright unnecessary by comparison.
Article here.

Thought it might be a helpful read for some folks.