The 2004 Miata is the same thing as the 2003 Miata. The only change is the availability of a turbo model that will be branded the Mazdaspeed Miata in the USA, the Roadster Turbo in Japan and the Miata SE in Australia.

For 2005 the Miata will move to a short-wheelbase version of the RX-8 platform but what kind of engine it will have is not yet known. It is equally likely that it will continue on with an inline four as it will get a rotary.