Being quite new here I would like to understand what is missing. My GPS is an etrex Vista. I generated a map of Michigan from OSM using mkgmap. If I go to Find > Addresses, I am able to search for adresses. I first search the street name (for example Jefferson Ave), then I go to street number and just hit OK. From that point I have a list of streets with cities that shows up.
The things I have noticed:
* If some ways are named similarly (Jeffersin Ave and Jefferson Blvd), all streets will show up if you select the first one. I f you select any other, the list will shoe "NONE FOUND".
* Some streets do not show up in the correct city (maybe this is due to some bad OSM data)