I tried finding this info as well, and didn't find much.
It seems some newer Mazdas (2010+) can be configured to enable it (I think it was the 6 and CX-9). No word on the 5. This is sequence of actions using the ignition switch and the locks. If you search the forums you may find it - if you do, give it a go and report back.
I would be suprised if you couldn't do it using the approriate software via the OBDII port.