I purchased a nice 03 Buick lesabre with only 40,000 miles mint , well after driving and enjoying it now for 2 months , I now have a red flashing light left top side of my radio. however it still works and it does go off when I start the engine , what does this mean because I pulled out the manual and this is what I have ,can anyone tell me if this is something to worry about or is it a normal thing that was just delayed in happening for some unknown reason?