One problem related to radiator has been reported for the 2005 Mazda RX8. The most recently reported issues are listed below.
I'm going in today for the third time because my ac continues to make a noise when the fan is blowing. I cant even begin to list all of the problems I've had with this car. Just to name a few I'm on my second engine, new brakes, battery and tires before 40k miles and I was told by three different shops that something is really wrong with the brakes but Mazda claims other wise. I've had a two new radiators and my driver window went out along with everything else from the visor falling off during the hot summer because it just melted. How does a "sun visor" melt. I've had the shifting paddles replaced because they just didn't work and I don't even really use them, the gas cap lock broke and I had to pry it open since the eject no longer worked. . . I think you get the point and I didn't even mention some of the bi items. I've never had so many problems with a car in my life. I cant wait until I can sell it or maybe ill get lucky and it will implode. It wouldn't surprise me at this point. This car is junk!!! I'm going back to Honda.