Cramming superfluous (or useful) extras into GPS receivers definitely isn't new, but Mainnav's trying to go out a bit further on that limb by adding an interesting feature that could actually be put to good use in the right situation.

ENGADGET: Mainnav MG-920 Bluetooth GPS receiver touts FM transmitter

Once the device syncs with a navigation unit, the audio is then piped to the Mainnav via a 3.5-millimeter audio cable, and if you're actually in one of those remote areas where an FM transmitter can broadcast something other than fuzz, you're good to go.

ENGADGET: Mainnav MG-920 Bluetooth GPS receiver touts FM transmitter