Xm To Sirius Satellite Conversion?

[gamlexus]

Just bought a 2013 RX350 with XM radio. I know XM and Sirius are now the same company but they don't use the same broadcast satellite. The XM satellite is lower in the sky and drops out frequently on my new RX due to trees. I have two other cars with Sirius satellite radio with no drop outs. My question is, on my other cars the satellite portion of the radio is a removable head unit, I can purchase an XM or Sirius head unit. Does the Lexus have this capability? I can't get an answer from my Lexus dealer. Does anyone have any information on the RX CD/DVD XM indash radio? I've owned the 2010 IS350c with XM and the same drop out problems. FYI, if you don't know which satellite receiver you have, you can tell by the ID code. XM is alpha-numeric for example; ABC123DE and Sirius is all numeric; 123456789.