That's the issue for me with an ipod, no built in GPS. It is possible on android as there as now several apps which can use the GPS functionality (AR Liberator, appradio unchained, ARUnchained GPS Injector). Is this feature implemented and it just isn't working for me, or is this something that hasn't been developed yet?
If it isn't developed yet, the same methodology used by the injector could help solve the issue (injecting mock locations from the radio to the ios device).