http://articles.latimes.com/2010/dec/10/business/la-fi-autos-buick-gnx-20101211 for the GNX with 136 miles. The Los Angeles dealership bought it from GM, tried once or twice to make a killing by auctioning it off, and never succeeded. They eventually decided to keep it as an investment they can one day cash in.
http://www.hemmings.com/newsletter/newsletter.html?volume=1&issue=45 for the 1969 Charger Daytona that kept getting shifted between two dealerships but never sold from it's Virgina home... til in 2004 someone recalled they had a gold mine stuffed away in the attic of the dealership and it went to Mecum auctions. I read about it in a magazine, but can't recall much about it.
tipped to the GNX from Jalopnik