Stereo Add-on Options?

[blueviol]

I am wondering if the stock Nakamichi system for SC400 has any direct wiring options for add-ons such as XM/Sirius or MP3 Vault.

I don't like the FM transmitter option for any of the add-ons, as the noise level is way too harsh.

Is there any way I can direct connect perhaps using the existing input channel ?

I am looking at the following combination:

Kenwood KCA-R71FM Add-on controller/FM modulator (also direct connect)

Kenwood KHD-CX910 the music keg

and a digital radio tuner/antenna.

Should I do some elec job to the amp or radio to get this work?

Any advice would be appreciated.