1) Unless you want to spend big dollars on a brand name cooler, the Hybrid-clone coolers kicking around work pretty well, their only downside being the stupid 3" outlets. Josh made 300rwkw with his 450mm version, although the 600mm version is often just as cheap. Stu has one of them in his GT4.
2) No idea.
3) Most pod filters will make the sucking noise. Make sure it gets shielded from the engine bay heat and gets a decent cold air feed, or you'll be down on power.
4) Once again, no idea, wait for some of the QLD guys to answer.
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