HEADLIGHTS ARE FLICKERING WHEN DRIVING AT NIGHT ALSO ONE FOG LAMP IS OUT ON THE PASSENGER FRONT IS THIS RELATED OR DO I HAVE A RELAY OR HEADLIGHT SWITCH GOING OUT

You most likely have a bad headlight relay or a bad headlight switch.

This can be caused by a bad fuse, or a fuse with corroded or poor contacts, or a faulty headlight switch, or a problem with your wiring. Start with the fuse, then try turning the headlights on and off a few times to see if that helps. Otherwise, into the shop ...

Judging by your description of the phenomenon, the headlight if the seal is very good, the car or the rain will not influent, explain this phenomenon should be fog, does not belong to a fault. When the owner found there were the fog lights, first analysis the causes of the fog, if it is caused by the difference in temperature or moisture, such as night lights use a long time, second days and found there were the fog lights, this time as long as open the light or light for 10 minutes or so, in the light of the mist will slowly disappear, please rest assured to use, without the need for lamp sealing treatment. Use obd2 for car diagnostics , you can improve vehicle safety performance and driving more safer.

The fog lamps are computer controlled .the body control module (BCM) will energize the fog lamp relay control circuit. The BCM receives the park lamp ON signal from the interior park lamps supply voltage signal circuit.
DTC B2527 Front Fog Lamps Circuit Low
The body control module (BCM) monitors the front fog lamp switch signal circuit in order to determine when the fog lamp relay is to be energized. When the BCM senses that the front fog lamp switch signal circuit is grounded momentarily by pressing the fog lamp switch, the BCM energizes the fog lamp relay by grounding the fog lamp relay control circuit.

Your best bet , take it to the dealer . Could need BCM replaced , would need to do testing using the Tech 2 scan tool . A new BCM has to be programmed .

Body Control Module (BCM) Replacement
If the body control module (BCM) is replaced, the following procedures must be performed in the following order:
BCM Reprogramming--Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems.
Important: This procedure has to be performed only for vehicles equipped with the Passlock™ System.
Theft Learn--Refer to Programming Theft Deterrent System Components in Theft Deterrent. A new BCM will learn the Passlock™ information automatically, but the powertrain control module (PCM) must still learn the theft information from the BCM.

Go back to the body shop and have them check the ground wires for the lights

Hi. Since the headlight on the driver side is working then we dont have any problem with the fuse or relay. Check the wiring and the socket of the passenger headlight if it is intact to the bulb. If it is intact, then this could be a headlight problem. Time to replace the passenger headlight.

The only thing that I can see and should make sense is the body control module controls the ground side of the headlight relay.

Maybe the control module is defective or the wire to the relay ground side.... grounds itself somehow which would also cause the flickering.

Probably not, the fog lamp relay works off the dip beam power, is there a relay for the dip beams?

SYLVANIA H7 SILVERSTAR HIGH PERFORMANCE HALOGEN HEADLIGHT BULB -- 55 Watts, Single C-8 filament for use as either high beam or low beam; 100 percent legal halogen headlight bulbs; Features the whitest and brightest light colour similar to daylight for safer night driving; Meets all US FMVSS 108 and Canadian CMVSS 108 requirements. Fits Driver or Passenger Side Driver or Passenger Side Fits the following vehicle/s
2004 Audi S4 Base 8 Cyl 4.2L 2004: Base; 8 Cyl 4.2L RAMPAGE FOG LIGHT, BLACK METAL HOUSING, With round clear lens; Includes 100-Watt H3 halogen bulb, one lamp and a single bolt mounting system; Provides better illumination Fog Light

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  Fits the following vehicle/s: 2004 Audi S4 Base 8 Cyl 4.2L 2004: Base; 8 Cyl 4.2L;