According to the document posted at Miata.net (registration required to see the image), Mazda will alter camshaft lift and valve size on both ... Except for the MR2. And without real competition ...

Toyota halted exportation of the MR2 to the U.S. in 2004, primarily due to slow sales and fierce competition from other manufacturers (read: Miata/MX-5). However, in the MR2's home country and in ...