My wife just bought a 2017 Crosstrek Prem. And would like a bit more acceleration. I’ve seen some different add-ons to include a billet manifold spacer, cold air intakes, and performance tuning. The billet manifold spacer is reasonably priced, around $300, and seems to be a quick install. Has anybody had any experience with this and does it provide the noted horsepower/torque as advertised? What other performance upgrades would fit a minimal budget for this particular car?