Yeah. It's possible to change the product ID on the empeg.

0x4f,0x08, /* empeg's vendor ID */
0x01,0x00, /* empeg car product ID */
0x01,0x00, /* empeg's revision ID */

It's set by the kernel driver for the USB chip. Twiddle the product ID to whatever a Rio portable is and it should identify itself as that. Probably a good idea to change the product ID strings as well. None of the empeg car protocol is in the kernel driver, it's all implemented by the player application by the looks of things.

However, If you mess about with the driver then you wouldn't be able to use the USB port to sync normally anymore unless you fudge together a method of selecting which USB driver to use.

- Trevor