Garret is the source.
I was going through the similar problem. I needed update for the maps (according to Z2 I drive half of the time in the field, a new division, z3 still has issues, but at least not plotting me through someones property/driveways)
I got my 80 gig lightning quick, put new HD and was done in literally under 5 mins. Sure now i have to reload all my music, and i kinda ok with that, since i had a lot of "mix" cds and organization was screwy. Now i am with clean slay, a back up drive just in case (original z2). Garret is the man to talk to. The only thing is the 80 gig is la