osm-garmin: improve Garmin map for driving

osm-garmin/app/build-gmap.sh

@@ -57,8 +57,11 @@ function build_gmap() {
             --country-abbr="$country_abbr" \
             --description="LN $(echo "${region##*/}" | sed -e "s/-/ /g" | sed -e "s/\b\(.\)/\u\1/g" | sed -e "s/ /-/g")" \
             --add-pois-to-areas \
+            --improve-overview \
             --route \
             --index \
+            --process-destination \
+            --process-exists \ 
             --bounds="$bounds_dir" \
             --housenumbers \
             $tiles_dir/$region_shortname/6324*.osm.pbf \