Well, I also wonder what they will done once they run out of existing parts.
They say that they will use 80% of existing parts, but they won't be able to make several thousands of cars with that, I guess.

It reminds also the recent story of BMW that built a brand-new BMW 2002 as all the parts were still available.
http://www.worldcarfans.com/5050726.001/bmw-2002-tii-old-into-new