I'd try and sell mate, they are trying to shut down the FM band down, it was scheduled for next year but got put back. FM will be obsolete in the next few years and people will need to upgrade to DAB or another system. Not sure if new cars have FM systems installed now. Failing selling it, I wouldn't bother developing if being honest.
Of course the above is for the UK, I know you have the .com so you will have to weigh that up.