Did you know that Garmin has an RV specific radio? (not just the portable GPS units, but a whole entertainment unit)
Here it is
--very interesting (looks like some OEMs have it installed--seems to be a little finicky until just recently with some software updates). Its a lot more functional than the Jensen or Axxera units Thor uses. As a bonus the display is detachable (its an Android tablet). (Looking at the Specs it even has two CAN interfaces so it could talk to the networks (OBD-II) in the RV!)
Unfortunately it looks like it is somewhat difficult to purchase (and a bit pricey approaching $900 or so)--much like the other radios you have to find an RV dealer/boat dealer willing to order one for you--don't think you can even get it off the Garmin website.
The other interesting thing is far cheaper, and probably more useful: Has anyone heard of "Borg Stabilizers"? Basically they are just a large grommet that fits in the wheel hole of your dually to hold the valve extension in place (Valve Stem Stabilizers