Hi Christie,
I didn't have a 2 door car with a newborn, but I did have one with my son who was 2 at the time, and a pg belly. I can tell you it was a hassel trying to get my son out of his carseat, even without a pg belly.
I cant imagine having a newborn in a 2 door car. I am sure you will chose whatever is best for you and your family
Lisa