It is said that Citroen decided that the limited 6 units of the GTbyCitroen wouldn't be worth the time, effort and cost that would have to go into making them.
Citroen's product head Vincent Besson previously admitted that the production model would carry a Ford V8 making at least 500-hp mated to paddle-shift manual gearbox. Sigh... it was a nice dream while it lasted.