Ah. Anyway, as for whether it will work. I'm glad I waited and reread this because I don't think I understood the question the first time. If I understand correctly, you have a car kit that comes with a USB power cord and you want to use the aux port to power the satellite radio and use a splitter so you can also use a thumb drive in that port (at first I thought you wanted to run audio through the USB and I thought you were out of your mind). There are several issues with this.
The USB port in the Sonic does not provide much power. I'm not sure how much it carries, but I can't even charge my phone with it, and it can't spin a laptop hard drive. I don't think it's a good candidate for powering an XM receiver alone, much less adding something else to it. If that doesn't turn out to be an issue, it would be possible to get power from it, but I don't think a standard splitter would work. You would have to splice the +5v and - 5v lines and leave the rest alone in order for the radio to recognize whatever else you plug into it. The better option would be to get a 12v USB power adapter. I got a 2 port adapter from 5 Below that lasted 3 years, which is about as long as the more expensive ones last. Of course, if you want a permanent install, you should splice into the radio's power circuit instead so you don't have cords all over the place. Hope this helps. Let me know if I'm misunderstanding completely.
