I followed the steps I saw other people applied to get a spare tire for the Model S. I discovered it doesn’t work: either people did not do basic tests or the spare geometry is different enough to not work in my car. The main problem: distance from the brakes (worse in the back); and with spacers applied it does not solve the problem since there will remain not enough bolt space to use to tight the spare.
The video shows the steps I applied when testing the X3 spare on the Model S. Details in the images.
After this test I tried a 18″ BMW 7 series wheel and the thing almost worked: it touches the under part of the air suspension. The next image shows how this component almost touches the original wheel of the Model S. So, it has to be at least a 19″, if not a 20″ to be on the safe side.
In conclusion: still in the process of finding a solution.