Hi mate, I ordered my GTD on the 14th February and its still with the factory. So 7 weeks and no word yet.
You get word roughly 4 weeks before its due to be built (confirmed build date) and then anything from 2 to 4 weeks after that for you to pick the car up.
With dealers giving an estimate of anything up to 20 weeks from order to delivery, I suppose that's well within it.
Did you order via a dealer or broker?