Good evening Ladies and Gents. I've never did a staggered setup before. I plan on buying these wheels http://www.elementwheels.com/proddet...d=mrrgt11985hs
on the site states tire size are need, 245/40/19 255/40/19

-Is it standard/ideal to space both rear and front or just rear?
-People with Staggered setup, how does the rear wear versus the front tires?

 

I have 245/40/19 front and 275/35/19 rear on my Rays 19 inch wheels. They are 8.0" wide in front and 8.5" in back. 275 is absolutely the widest you can run on 8.5" wheels, and there is definitely some buldge. 255/40/19 will be a few mm taller than OEM, but should work fine. Use this calculator to check wheel/tire diameters.

http://www.miata.net/garage/tirecalc.html

I'll also advise you to try to find a set of used Rays 19" wheels instead. They came standard on the 2005-7 coupes with the 19inch wheel package and I believe these look best on our cars for people looking for 19" wheels. I got mine used for $480 (total for all 4) on craigslist. Lots of people swap out the wheels on the coupes, so there are usually deals out there on used ones...

You shouldn've have to add spacers if you get the right offset. I'm running +30 front and +33 rear on the Rays wheels, and it looks fine.

If you go staggered, make sure you don't get directional tires. Asymetric is fine. Since you already can't rotate front to back, directional tires will hamper your ability to rotate even side to side. The rubber would have to be removed from the wheel to rotate side to side. That's the only caveat I have. My paws are the Continental ExtremeContact DWS, and they're asymetric.