Can I modify Ice>Link to provide line in?

I had an Dension Ice>Link installed shortly after I got my 2005 Prius. Worked great with a couple of generations of iPods, but now that I'm using an iPhone, I'd actually rather use the iPhone's display to change tracks (particularly with FlickTunes).

Of course, with the ice>Link plugged into the iPhone, I have to use the car's controls to switch playlists and tracks, and it's always been sluggish. And of course, the ice>Link doesn't charge the iPhone.

Is there any adapter that I could plug into the ice>Link that would give me a simple line-in connection for audio? I've done some searching and there is a Griffin adapter that lets you use Shuffles with dock connectors. Anyone tried that, or is there something else out there similar?

Thanks.