PDX Transit

According to engadge, Volkswagen is planning to release a plug-in "Twin Drive" hybrid in 2010
 http://www.engadget.com/2008/06/27/volkswagen-prepping-a-plug-in-twin-drive-hybrid-for-2010/
Why does it take the American automakers so long to do this?

London's Heathrow Airport is set to install the world's first Personal Rapid Transport system. The PRT is a fleet of 18 driverless pods for business passengers flying out of Terminal Five, with installation scheduled to be complete in less than two years. Traveling at up to 25mph, the pods will ferry passengers rapidly between their [...]