I run one on my Jeep and just tightly coiled the wires up, tapped the heck out of the tiny module and zip tied it off the transfercase connector harness mounting tab. It is out of the way of driveshafts, the heat of the exhaust and protected by the skid plate from snags.
If I am not mistaken they claim it is waterproof or water resistant, I don’t recall off hand, but I felt wrapping it in electrical tape for good measure wasn’t a bad thing.
My Jeep isn’t a daily driver, but it has seen its fair share of water and never had an issue.