You can go into dealer mode by holding down the following buttons for a couple of seconds: drivers side up temperature, down temperature, and front defrost!
You can't really change any information on the screens.
Some options are available on the navigation models that are not on the non-navigation models, obviously!
These shots are from a navigation model!
As you can see though, you apparently are able to backup your data and restore your data.
Some radios have an Engineering Mode, which is entered by holding JUST the driver's side temp up and down buttons. Some good stuff in there, like enabling the DVD in-motion.
It works on ours, too; I found it about a year ago on the first RB5 that I installed in my Charger.
Sadly, it was a 2012 model, so it didn't have Beats or Sport Mode, so I replaced it with a 2013 that didn't have Engineering Mode. There are a few folks who can get into it, but it's rare. There may have only been a small window of time in 2011/2012 when it was available.