Mazda's Nagare line of concepts seems to show a few different brand faces, for different segments. The car at the top of the page is the Kabura concept though. And if the wiki articles means anything, it represents their sports car line, and would be an MX-4 should it hit production.
As for the R&T car, well, it doesn't look anything like a Mazda. Take the badge away, and the only things I see are the grille being a little Mazda-like and the hood giving tribute to the rotary engine also found everywhere on the RX-8.
And naming-wise, I think RX-9 is a same bet.