I tried one once, as soon as i got my car on Oct.3rd it was on the mitsubishi site i think i dont remember?!?! but you have to basically download 3 files 3 different ways or something!? and it took me about 2hours and it didnt work it didnt make sense to me! i think mitsubishi will offer an update but who knows how much $$$$
I asked this a while back, see http://www.lancertuners.com/modules.php?name=Forums&file=viewtopic&t=1397 Basically was told it's coming soon, but that's about it.
This link is just for updating the Gracenote CD Database, it does not update the navagation system (maps, street names, POIs, etc).