Hi, I have a fairly standard 2004 Wagon, it has 4" full Cobra ss exhaust, no silencer, just the back box, ss, Cobra downpipe with a small sports cat, K&N typhoon induction kit with all fittings and imported manifold thats it so far on the go faster stuff for now, took it to Xi Mitorsport for dyno and remap, they were astounded by the results, I was open mouthed 310.2 bhp no mechanical upgrades, well chuffed, if I take it easy, its noticeably better on fuel too, though not much.☹ as has been said many times, improve the air intake and exhaust first, loads in, loads out.

Impressive gains , any more plans for the wagon ? 

Thanks, I may go the turbo route, with a front mount cooler, bigger valves, but only being 2ltr I dont want it to go rice crispies, snap, crackle POP! Fine line between tuning and over tuning where you put too much strain on it. Cheers.