Theoretical you can run Garmin almost on every Mio Moov/Spirit models, because Mio runs on windowsCE OS. But as we know (or maybe you don't), there are plenty of Garmin XT versions for wince, but none of them doesn't run smoothly and come along with lots of problems..Garmin is linux based and all "unofficial" attempts from hackers to recode it to windowsCE wasn't 100% succesfull so far.
Anyway, you have other great solutions - for eg. - iGO navigations works perfect on Mio devices, but in genearal you have to "unlock" your device first in order to install different SW on it.