My Navigation screen went black shortly after purchasing a used Cruze 2012 LTZ. Dealer wanted around 1200 to replace the main unit, with the help of another member on this forum(ezap28ltz) I learned all I needed was a gmos-045 to install an aftermarket stereo and to retain the Nav screen with climate controls above the new stereo. GMOS-044 does work for chimes, parking assist, etc. for the base models but you have to have the 045 if 7" Nav is in your car. THANKS GUYS!