Well when I bought my car and I bought my whole system they warned me that the keyless entry and the dome light would not work if I completely took out the factory stereo. I wanted all this to work so they installed the new deck but they still had the factory hooked up to the dome light and the alarm, don't ask me how since they installed it, but I do know that the stock is behind the dash area, right behind the power outlet. You would never know it is there.