I've got 3 locations also, actually 4 ... only because I added my Furrion Observation Camera side cameras and if I installed them in the same spot as the original side marker, the baggage door hinge would have blocked half the view. So, I installed them higher, so actually there are 2, one higher and the original up front.
Now, I used the red / white reflective tape on some key places on my Montana also. I put tape on each slide so it could be seen from the front or the back. And I put it on all the slides. I also put the tape on my solid steps also. My camper has a back door on the opposite side. It's uncommon to see a camper with a door on the "other side", so when parked along the side of a road, or even at a truck stop, oncoming traffic from behind just do not see the steps on the passenger side. So the reflective tape down the side of the step does help.
I put some on the rear, under the hitch frame so it can be seen from the rear. But I never thought about putting any in the middle, under the frame.
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History is not about the past, it's an explanation of the present.
2019 Montana High Country 375FL
2014 Chevy Silverado Duramax, 6.6L Dually