I have a 2013 Charger RT with the 8.4 inch Beats Audio stereo and screen. My question is: Is there a way to update the sales codes on my own without going good to the local stealership? The car did not come with the back up camera and I've been thinking about buying one to install, but I read that the dealership needs to update the sales codes for it to work. To me, $85-120 for a 5 minute job is a little excessive. Any suggestions?