Backup camera install

[MatthewMD]

Has anyone had any luck adding a backup camera without replacing the stereo head unit? My 2013 LaCrosse has a touch screen MyLink. Also, is the wiring already present in the trunk or does a cable have to be installed if not going the wireless route? Any recommendations on cameras to get as close to factory would be appreciated. I stopped to talk with an installer, but they recommended a new stereo unit from seicane.com, but they don’t seem to have the matching year/model replacement.
Thanks