Good idea. I have one that I am using on a 930 restoration. My garage ceiling height is 10'-0" and with the car on the rack - I can run the top of the car into the ceiling. So I have to watch that, but with it extended (with clearance above) I can fit my 2010 M5 below the Porsche.
I don't drive the M5 in the winter - so I park it below the Porsche and my winter car sets in the other space where the 5 usually sits.
Heres at pic
