Hey guys. Just bought an Escalade after selling my 2007 Silverado. This truck is fully loaded minus the power running boards and the backup camera. I've recently added 24" Dub Dirty Dog rims and installed the OEM navigation system. After installing the navigation system, it read THEFT LOCK, so I went to the GM dealer and they unlocked it for me. Now I can't seem to select the "5.1" mode under audio. I can only listen to music in the 2.0 mode. Is this normal or is there something wrong? Also I want to install the backup camera as well. Is everything already pre-wired? Where can I buy the camera? Thanks!