I installed a Sirius receiver in my 2005 E320 cdi. It mounts behind the right rear trunk panel on sedans. You should be able to buy the kit for around $600-700 including 12 months of service. I mounted a small (magnetized) Sirius antenna on the roof which works very well. The MB Sirius receiver integrates with the Command system without needing to be initialized by a dealer. Good luck.