Build a factory to mass-produce flying cars

To prepare for the final half of the 21st century, I want the government to build a factory that would mass-produce a modernized version of George Jetson's car from the classic animated series "The Jetsons" (if you don't know what it is: http://en.wikipedia.org/wiki/Jetsons) And make sure these cars are able to fly just like on the program. The factory can be placed wherever you like it, but most especially Detroit. This is just in case every building in the world is placed up in the sky. I wonder how whoever is president in, say, 2113, can be able to get to the White House if it's in the sky as well as all other buildings...