Please check the listing for this "rare" car.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300254905097
At least the questions were honestly answered and the seller acknowledged that the car is not, and never was, a Z/28.
John, did you read the questions? Did a few X11's get changed to Z/28's? It just seems like the seller is pushing this car as a rare Z/28.