2006 Pontiac Grand Prix 2006 Grand Prix GT Headlight Failur

I have a 2006 Grand Prix GT with just over 53000 miles. For the last couple weeks the headlights (driver and passenger) have been cutting out while driving at night. All of the other lights (high beam, turn signal, fog lights, side markers, tail lights and brake lights) all work properly. There are no other issues with the car. There seems to be no pattern to the lights cutting out. If I change the switch from auto to manual after they cut out they do not come back on. Also, I noticed that when they do cut out and I shut the car off and unlock with the fob the lights do not come on at night as they should. Usually after cut out, within 30 secs to 2 minutes they will come back on without me doing anything at all. I've never been able to meter the sockets for voltage during a cutout because they never fail when I'm waiting for it to happen. I've never been able to determine if they fail during the day. Any help or guidance as to where I may look next would be appreciated.