XM Radio Personal Playlist

Does anyone know if XM has a feature to provide its users with a personal playlist option?
How cool would it be if you are listening to a song that you like a lot and you click a ‘SAVE’ option in the menu to save this song in a folder on a remote harddrive partition assigned to you as a user, which can be accessed when you are connected to the XM radio either in your car or online.
Have a separate dedicated channel for a ‘User Playlist’.
I would love this. I think users won’t mind paying an additional $3 - $5 per month for this kind of service and renting the remote harddrive space.
Thoughts? Ideas? Comments?