My father bought a GF8 WRX NZ new in 2000, only thing that has gone wrong with it in 17 years is the plastic radiator header tank thing needed replacing. Its been up ski roads, driven hard, towed stuff, its still on the original clutch 250,000K's later! I've no doubt if you looked after a WRX correctly you could easily reach 1,000,000K's without replacing any major components, interior will fall apart before the engine.