Squid,
It might be a chore to get up there but, getting it down would be easy and that is when you need it.....I have rarely changed a tire in the last 20 years so, though I believe I need one, I would rather it be out of the way and not impeading my backside view. It seems to me that the main problem is that one would have raised the center of gravity of the vehicle quite a bit. Humm, might get a Chaser trailer and mount it on top of that.....
Phil