Yes, E5M1R, you are correct, but this is obvious. More importantly I forgot to mention that currently clear channel is the only provider for TMC/RDC and they only relay that through a Siemens/VDO interface which may be problematic due to the MKIV nav and the BM53/BM54 radios being Alpine units. It seems as if an external TMC/RDC receiver is the only option. Some one more knowledgeable about this should hopefully chime in.
---------Kham