I do not believe an FM modulator is in the plans. There are already plenty of third party products which fill this gap.

But I must say, I much prefer going this route. The quality is much much better than an FM modulator would be.

I've now got a small 1/8" jack on the dash of my wife's car (in the side of the goody pocket below the stereo) and we keep a short 1/8" male-to-male cable in the glove compartment. When I get into her car, I just bring the Karma (nothing else, just the Karma itself, it's got more than ten hours playback time with a charged battery) and we can listen through her CD changer input.