We have a weather station, ie hi/lo temps every 24 hr period current indoor/outdoor, humidity, pressure. Bought ours in Costco for $25Cdn. I just have a screw with the head sticking out and it is a snug fit in the hole provided for mounting, so far has not moved. The remote sensor fits inside the tube (support for the spare tire) there is a small hole at the top of the tub and use a zip ties trough it and the sensor so it can't drop farther down the tube. Because it is behind the wheel it is never in direct sunlight.
When we are home it is mounted in the house. Range for the sensor is far enough that when the MH is parked I don't have to take the sensor and relocate it.