Don't feel bad about contacting them for an update....they will be able to check their system and tell you whats happening, i.e. its been built, or its on the boat, or its at the dock waiting to be transported to the dealer.
They will be able to tell you the latest expected delivery date, but that is subject to change - they can't guarantee that until the car is on a transporter to the dealer, but they should be able to give you a good idea.
Some dealers seem much better than others at keeping you informed....mine was very good, but I must admit I did most of the phoning, but he never got peed off with me (well, he never let it show!!!).