Have to agree with CEGeek, I've tried and tried, to no avail.
I purchased mini-USB to full female USB adapters, microSD to full size SD adapters and tried them with numerous USB and SD wifi cards. Host capability just doesn't seem to be built into most of these devices...and for a good reason...it takes more to build them that way.
Normally, if you plug an USB or SD wifi card into a CE unit, the first thing you will get is an request asking for the drivers. If you don't get that, then you can be sure the card was not even recognized as being new hardware. And that is a hardware thing, not just a simple registry edit.
I've tried with an Nextar GPS unit, a Navman, an HP310, a generic 5" MStar 5321 based GPS, a 7" Mediatek GPS, a Garmin Nuvi, and others. Never could get anything but client usage from USB, and simple memory storage from SD slots.
But did you mean the Mio C320
(not C230
)? That is one of the few GPS that does have an SDIO slot...and of course there are a few CE GPS units out there with built in wifi as well. If so, then read
HERE!