Getting FIRMWARE (Software) will be the issue as it is 'technically' supposed to be done by a Mazda Dealer.
But you order the Parts from Mazda Parts Department.
Mazda Dealers in Europe already are selling Genuine Parts.
For USA and Australia it is September.
Firmware for 70.00.021A EU N (Europe) is already out in the wild at the 3 Rev Forum.
Only a matter if time before it is available for NA N , and 4A N, USA and AU.
AND NO DO NOT INSTALL THE WRONG FIRMWARE.
Check out the link above, I have the CX-9 and ALL Mazda How To install in it.
Mazda Parts Dealer pricing should be pretty reasonable 220.00 Euro, so that is about what $210 USD, I would wait until official release, you only have less than 4 weeks.