[Holyterror]

Since good mounting locations vary from vehicle to vehicle, I'll have to be kind of generic. But there are some universal truths.

The further away from the exhaust manifold, the better. That's where your charge picks up most of its heat. If your charge has to pass through the radiator, you'll get heat there as well. Low-mounted CAIs are quite popular, but water can definitely be a problem. A deflector will cut it most of the time, but you'll need to do better if there is a chance the filter element will actually be submerged. The AEM bypass valve (which, of course, fits their CAIs) comes in handy in this case. It works so well as to be overkill, from what I understand. Certainly something to consider if you're getting an AEM intake anyway.

If you're looking into a homemade or custom intake, your options open up a bit more. I am a big fan of cowl induction, because you are drawing air from a high pressure area, far from heat sources and dirt. Keeping your element away from dirt will marginally improve its efficiency, and noticably increase its useful life. If you spend a lot of time in traffic, a low-mounted intake might soak up a lot of other people's exhaust. There's been a lot of construction around here, and I've noticed what I believe to be tar residue on my undercarriage. Unless you enjoy washing your filter, you'll want it in a clean place.

These are just some considerations. In general, you just want to improve on the stock filtration by drawing in cooler air and bypassing needless resonators, etc. There are plenty of decent CAIs available off the shelf that will meet these requirements.