I've just replaced my battery today after the one it came with went naff and the car wouldn't start. New battery is now in (against all odds... the people who told me it was an easy swap were liars, getting it into that little space!) and the engine starts! Hooray!
However I am concerned - in the manual, as part of removing the battery it mentions removing/reinstalling a vent hose. The battery I removed (a DriveTec battery) did not have one to remove. The Evilution page about removing the battery also doesn't mention it - however I've since seen it DOES on the page about battery specs.
I've been able to see a brief shot in a video of maybe a tube going from the side of the battery into a hole in the car floor... but that's it. There was definitely nothing like that there when I got it.
Can anyone explain to me like I know nothing about it (because I don't, I had never heard of these until today or touched a car battery until this weekend) - how worried should I be, and what should I do?