That mean you don't own that car. Its the government car that they have given to you under a granted permission to use it. Same goes for your house. All they need to render the third amendment void is taking back their granted permission. Basically we are now describing a capitalistic governed country like the US as if it worked like an communist controlled one.
So before I continue down this line, do you really claim that government is the rightful owner of everyones property? If not, then we must separate physical property with government granted permissions.