George-- I'm in a similar situation as Cecil, actually, and have been following along. I'll need to grab my member number when I get home later. I have a 2016 AWD F-Type R coupe on order as well. The order was officially created on 11/23 (I have all the order numbers if that's relevant); build date is 2/20/15, factory complete date is 3/2/2015, and delivery date is estimated as 4/24/2015.
So a build date in March (or February) very likely does mean delivery in April, if not late April or early May. At least for me...
I'll follow up with you directly later tonight with the details on the specific dealer for my order and my membership info. I'm looking forward to hearing about 16MY programs when they are announced and go into effect! I'm guessing/hoping that this will be in April before our MY16 cars start arriving. That would obviously be my preference!