Mark,
Thanks for that update. I ran into that problem myself. When I ordered my new '06 early this year I read the posts here and ordered the XM adapter from Radios and More. It didn't work when installed.
My truck has, I think, the RBQ radio, with 6 disc CD, Sirius, and U-Connect. The friend who helped me install the unit was formerly a Dodge dealership mechanic and is knowledgeable of the products. It was easy to install the XM unit but when complete the in-dash head unit displayed Sirius information and the XM was silent. We couldn't find the Sirius unit. We removed the back seat assembly and searched under the dash for the Sirius unit to unplug or remove it but had no success. I reviewed all the TDR posts on the subject and spoke by telephone with a couple of members who had installed the aftermarked XM units in other model trucks. I talked to a local sound system retailer and was told the Sirius feature was probably contained inside the radio head unit and could not be removed. The local Dodge dealership was clueless. I gave up and have learned to live with Sirius but still prefer XM. I could hang one of the Roady units on the dash but don't want the clutter.
There have been many well-intentioned but incomplete posts here on this subject but most posts overlook the fact that there are differences in the wiring and electronics between model years 2003-2006. Some TDR members have written of how easy it was to install in their truck but the aftermarket XM units don't work in all trucks. There are numerous different "radio" units each year and also between the various model years. 2006 alone offers a base radio, a single disc CD, a 6 disc CD, a cassette and CD, one with the GPS navigation unit, one with blue tooth "U-connect", units with or without Sirius, etc. Some of the features I have just listed are combined into one specific unit and others are separate and different head units. Without detailed and specific information from Dodge and from an aftermarked manufacturer it is hard to know what will actually work.
I would like to buy the unit Bernie referenced above but I really don't want another expensive electronic device to put on a shelf in my shop building next to my XM adapter if it turns out not to work in my specific application.
If anyone has specific information about what aftermarket products will work with the '06 Can Bus electronics and which radio units I would be happy to buy another product.
Harvey