My Grandfathers both pronounced it "two dur and four dur" Definitely not "four door or two door". That's the way I've heard most of the past generation pronounce it so that's how I do it too. However, it was always put together with sedan, as in: "Tudor Sedan or Fordor Sedan". I'm sure the pronunciations were regional as well. Go back even 30 or 40 years and there were much more distinct accents/dialects. Everywhere except where I grew up, we didn't have an accent, just everybody else.
