I fitted one inside a bit of plastic tube, after I cut a "window" in it with dremel, drilled 2 x 8mm holes one at each end throungh which a screwdriver goes, 180 degrees opposite a 3mm hole for the screw screwed into the area at rear of roof as this is always double skinned, the cam has thin foam tape around it to make it snug but this stops the vibration, sits horizontally, cam can be taken out of tube easy if needed but very well protected like this as well.
I didn't take pictures at the time, it was actually on a Ford Bronco, from memory might have been a blazer did it for a GI, I will see if I can get piccie he said there was no vibration issue or anything and worked well it was around 3 1/2" to 4" long from memory.Sounds like a good idea. Can you post a picture of your install? Thanks.