And don't forget that with fully automated cars that can at least roll a few meters without starting a combustion engine (e.g. hybrids) you can park the cars without having a "road" between every two rows of cars, reducing space. Similar to this, just not with shelves but the cars themselves moving:http://www.rollster.de/picture/upload/Image/8780a17bd3128fe2... Also, garages would not need to be standing height, only lit on demand etc.