As far as I know - the two are separate - haven't seen any combo sirius/xm recievers. As far as hookup - you need to find out what you have to work with in the car. If you got AUX inputs on the back of your head unit then you are good to go - otherwise, you have to get creative in getting the signal to your speakers - if you want to do without the FM modulator. Some factory units do have inputs - some do not - just have to check. Usually they have a plug in the front of the unit or have an available "plug" that you pop into the back of the receiver/head unit.