Rio Receiver kernel question

Hi, can someone who knows answer this.

Is the kernel in the rio Receiver the same as the Empeg/Rio Car kernel [i.e. based on the same source code], and if so, does the Rio Car kernel changes released under GPL have the Rio Receiver 'specifics' in the code, or is there a second set of 'Rio Receiver' Only GPL kernel code somewhere?
And if so, where is can I find it?

Is the kernel in the rio Receiver the same as the Empeg/Rio Car kernel

No, it's a different kernel than the Rio Car kernel.

is there a second set of 'Rio Receiver' Only GPL kernel code somewhere? And if so, where is can I find it?

It is included on the CD-ROM that you got in the box with your Rio Receiver, in the "Source" folder. Have a look there.