Is this your app? I take it you are doing this. I'm doing an open sourced media app in linux in python using pygame and I'd love to have GPS in it. Do you plan on doing like an SDK where it can be built into another app. I know thats a bunch of work.
Even if you do something like send next directions into stout or something. This would be a big boost to the in-car linux world. The app looks great.