I have been doing some reading on here about the aftermarket Nav Units for the E53. I currently have a 2005 E53 with OEM MKIV Sat Nav, DSP, and Sirius Satellite Radio. I would like to replace the OEM unit and I am considering the Dynavin and Hualigan units because the have the look of the OEM unit and seem to have the most features. However, there seems to be confliciting information about whether or not you can retrofit these units into a system with DSP or not. Also, I can't find any information on whether or not you can still use your Sirius Satellite radio with these solutions. Will this basically be lost? Finally, will I lose OBC and MID functionality? I would appreciate any input.