I was wanting to get a CAI...
 

Keep in mind, as dumb as hell when it comes to car stuff, so I forewarn you that stupid questions will ensue.

What's the best one for my car (2005 Civic LX Automatic)?
What are all the downsides to having a cold air intake?

downsides are hydro lock.....which wrecks your motor! plus u have an automatic so it isnt gonna do too muhc for ya at all besides make a little noise

if you live in an area where it floods n rains a whole lot, dont get the cai, if youre wanting a lil bit more hp, just go with a ram air intake, no worry about hydrolocking with those

I have an aem cai (one of the best) on a automatic. Doesn't flood over here but only thing i dislike is that i have to take the bumper off just to clean or replace the air filter.

That's probably the worse part about it. Hydrolock is obviously something to think about too though.

Some people say Injen is the best for CAI's.

When we're talking about water...how high are we talking?

most of the way up to the top of your front bumper