Purchase a touch screen radio 2012+ and its plug and play as far as I know. If you get a post 2012 you may need a pin to unlock it make sure you get one or make sure the unit dont need one. Nav will work as well if you get a 2012+ and have sirus it uses that antena for the signal or you can just buy one.
Next you will need a rear camera find one for a chrysler 300c the cmos ver is lower quality the ccd is higher quality I got one from amazon for 20 bucks. Its a direct fit. You just unscrew the license plate light remove the bulb place the wires from the new led light into the original harness and tape it up and stuff it back in the hole. the wires for the camera will go in that same hole then up through a vent in the trunk just to the right of the trunk latch under the carpet on the back wall.
then get a lockpic v5 from costal e tech from solidsignal at there web page
it looks complex but is simple. Direct from them its 205 shipped or you can get on ebay / amazon for 230 ish.
there are also other lockpic devices but thats the one I used.
Spend 2-4 hours running wires and you have a back up cam. You can also add a front or left and right cams nany cam the lockpic has several inputs. It just takes another 30 min and 30 bucks to put a front one on and never have to worry how close you are to that block when you park
You will need new self tapping screws since mine didn't come with any and the stockers were too small for the holes in the new housing. Just found that out today. When I get this done I will put up pictures with wiring and how not to destroy the stock harness for the license plate light. I found an adaptor that makes it easy.