That is currently your only way of getting RG on the car-player, and then only for MP3.

Which is why I think the best approach (for the car player, anyway) involves revisiting the ill-fated per-song gain adjustment feature that almost made it into v2. The only downsides are that it requires a first pass through the song to do the calculation, and the gain isn't stored in the music file itself, rather, in the dynamic data partition. I'd be willing to live with both of those restrictions on the empeg, but I'm told that the whole concept doesn't translate well to the portables... So I won't hold my breath for this one.

The idea of a 3rd party application (perhaps the one I'm developing) doing gain adjustment has been talked about, but I'm not quite confident enough in my kernel abilities to give the harder parts a shot. If there were an easy API I could call to apply an X dB or X percent gain to the current player volume, I'd be happy to support one or more of these gain adjustment standards... Just haven't seen anyone willing/able to take a stab at the kernel stuff yet.