Rockbox and the Harman Kardon Drive and Play

[bimbim18]

I'm guessing Rockbox  won't work with the HK Drive & Play?

anyone have any experience otherwise?

[saratoga]

Theres a list of supported targets here:

www.rockbox.org

And a link to information about supporting other devices.

[soap]

I assume he is referring to an automotive head unit which controls an iPod?
In which case there is not currently support for the Apple Accessory Protocol in stock rockbox.
See http://www.rockbox.org/twiki/bin/view/Main/IpodAccessories for a start.
Then see http://www.rockbox.org/tracker/task/8624 for a source code patch which starts support for the Accessory Protocol.
Then see http://forums.rockbox.org/index.php?topic=17841.0 for an unsupported version of Rockbox which contains said patch.
Note - you have a good chance that audio will work w/o the patch, but no chance controls will work w/o the patch.