if its a really rainy day, and theres huge puddles in the road (which there often is with the shit sydney roads), if you just so happen to be on full throttle (which you shouldnt in the rain with a CAI) the filter will suck up all the water and ur effed. but i believe it does need to be quite a big puddle lol.

in regards to the mods... i kinda gave up tryna find power for the k20z1 based on difficulty in finding quality parts with gains and also lack of tuners for the engine. Most tuners are more familiar with k20a and k24s or the k20z in the dc5s. But despite that, I'm sure you'll be able to get some guidelines from guys in the states who've done pretty decent mods to their civics and made good power both NA and after FI.