I bought the suction cup and that works decently as an in-cab mounting place.
I've also Mcguyvered a couple temporary external mounting locations. One is via a bolt location on my mirror relocation brackets. Another is on the top of my winch's roller fairlead, using the holes on top.
Bolt location on the driver side mirror relocation bracket (with camera).
Bolt location on the driver side mirror relocation bracket (without camera).
2 bolt location on the winch's roller fairlead (left side is without camera, right side is with the camera).