OSM for Cars

is there any project around that converts osm-data into the propietary formats of built-in navigation systems of cars? Haven’t seen anything on github.

I am not aware of any, but it has been mentioned before: http://forum.openstreetmap.org/viewtopic.php?id=21687

For myself, I find that with monthly map updates for OsmAnd and/or approximately weekly updates for Maps.me (if looking at their “daily” directory) running on my phone I almost never use my car’s built in navigation system.

At least some Kenwood units are rebranded Garmins, people occasionally mention that they’ve got OSM maps working on there.

Other than that I think the answer is basically “no”.