I've been running this setup for about 3 years. I wired mine in using an OEM nissan blue relay wired into the fuse box so you can't tell it's aftermarket. The cheap relays I used to get would fail every so often and I got tired of it.
Also, Yury didn't purposely not wire in the fans, the fan plug comes off the chassis harness, not the engine harness. Don't listen to that guy.
Here's a diagram I made up in paint. It's pretty straight forward, hardest part is finding the signal, and even that's easy. One of the wires on the wiper motor gets constant power when acc is on, so I'd use that and avoid running wires to the interior. Also, don't use relay connectors with small gauge wire, they will burn up
