Holy cow, thread revival!
Anyways, it can be done but costly. These flip-key/retractable keyfobs actually have 2 components 1) the remote piece, and 2) the actual key. These two components are then put together to form the single flip-key. You need the Mazda Axela remote piece (
D436 67 5RY, this is the expensive and hard to get component), and the actual key from a N. America-spec Mazda5 (
G2YA-76-2GXA).
See the latter pages of this thread:
http://www.msprotege.com/forum/showthread.php?t=114423
Can you use the Mazda5 remote piece (so use both the remote and key from the Mazda5), that I don't know.