Adding Garmin IMG format

Related products: FME Form

Garmin IMG is a proprietary format, many Garmin GPS users would like to add their own maps in their handhelds. Ability to write into this format would help a great deal .

Is there a way that FME can "bypass" the native format of .img Garmin (or intermediate format?) so I can create a transparent map to add on top of an official Trackmaps in both BaseCamp and GPS?