I can think of at least a dozen buildings in Toronto that use some form of a parking stacker system. And I am seeing firsthand how they are becoming more popular and more commonplace as a result of space constraints, rising costs, and a bunch of other factors. Below is an example of a system that allows you to (almost) triple the number of cars that can be accommodated on a given footprint. However, it does require higher floor-to-ceiling heights and a pit. If you can't see the video below, click here .
https://youtu.be/lDbMnNMdFFg