Unlikely because you'd have to fit all 4 and test drive it, plenty of 2nd hand suppliers out there with that size, one in Forrestfield and another in Balcatta from memory but the standard WRX rim will drop straight in so compared to what you want.

Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
205/70-15 5.6in 13.1in 26.3in 82.6in 767 0.0%
215/45-17 3.8in 12.3in 24.6in 77.3in 819 -6.4%
Not a huge amount of difference but your speedo will be up to shit and the gearing won't be as good off road.

Better option if available would be

Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
205/65-15 5.2in 12.7in 25.5in 80.1in 791 0.0%
215/45-17 3.8in 12.3in 24.6in 77.3in 819 -3.4%

From here

http://www.miata.net/cgi-bin/tirescgi