Hey David, you still around and programming?
I'm not sure if you are up to this, but I realized today the best way to use GooPs as a nav system... don't

.
iG3 + GooPs together would work perfect if we could only integrate them together. The top-view in iG3 sucks! It places your car on the bottom of the screen so if you have any turns you have to zoom out a ton to see the full path. Sometimes you can change from heading to north, but it's still no zoomed out Google Earth. Conversly, GE sucks when zoomed in as you don't get the "hybrid-view" road overlays.
I just always use iG3 in 3D/Heading view to show me turns and announce turn-by-turn directions. I'd rather use Google Earth if I want to look at a map should I decide to stray from my route a bit. iG3 will recalculate and keep giving me it's directions as I modify its path my driving an alternate route with GooPs map as my guide.
...so here is the software request: Make it so whenever I choose a destination in iG3, GooPs automatically routes it's own driving directions from the current GPS location to iG3's destination. This way I have the route highlight in both programs, an awesome map with traffic conditions overlayed in GooPs, and turn-by-turn directions from iG3.
If you would like to be on-board but do not know how to get a route from iG3, maybe I could do that part and you could just make it so when GooPs receives a window message with co-ordinates (or an address) from my app, it automatically routes directions from the current location to those co-ordinates in Google Earth.
Possible?