I have an AEM V2 cold air intake on my civic. I have the splashguard underneath it, and I am still careful when I'm driving in the rain. I try not to go through any puddles, the last thing you want is any water getting into the filter. Hitting a puddle every now and then isn't going to cause hydrolock, but it still isn't a good idea hitting them. For some air intakes you can get a bypass valve that if you do hit a puddle it won't go into your filter. The AEM V2 says not to use it, because it actually robs performance. You should be fine as long as you don't submerge the filter.