Rims that come off an E46 M3 will NOT fit on your car, the offest on a the M3 rims is far too aggresive to fit on your car. Not only that, but 275/35/19 are too wide tires to fit on your car.
As far as widest tires you can use,
Well... going by...
http://www.miata.net/garage/tirecalc.html
235/40/18 Fronts
and
265/35/18 Rears
But... time to bust my math skills out...
Well... for what I am running now...
225/45/17 F
255/40/17 R
Considering that 1 inch = 25.4 mm
Front: 225/25.4 = 8.8.....
8.8.... * .45 (45% of width is tire profile) = 3.9....
3.9... * 2 (top + bottom) + 17 (wheel size) = 24.97...
So the factory front setup is 24.97 inches tall
I'll spare you the explanations for the rear..
Front 225/45/17 = 24.97 inches tall
Rear 255/40/17 = 25.04 inches tall
Now to compare to what we think will work...
Front 235/40/18 = 25.41 inches tall (SO..... 25.41 - 24.97 = .44 inch diff)
Rears 265/35/18 = 25.30 inches tall (And... 25.30 - 25.04 = .26 inch diff)
So.... going by all this, tallness shouldn't be an issue... only question is, will they fit due to width?....
Now, again using that website...
FRONT....
REARS.....
Let me know if you have any other questions