Headlight Condensation

[bob.rossato at att.net]

> The ur-quattro suffered from this problem.  It wasn't the seal or cracks in the 
> glass - it was
> the fact that the rear plastic housing was made from a thermo-plastic in several 
> pieces and
> heat-fused together.  Tiny cracks - barely visible even to a trained eye - would 
> develop in
> the rear of the housing.  The headlight got warm in operation, and when it 
> cooled down the
> contraction of the air within sucked in damp air from outside.
> 
> 24 years on - could it be the same problem?

The newer headlights have vent holes built into the back of the housings.  The headlights on my '95 S6 do, and the '00 A6 headlights I looked at do as well.  They're not obvious as they're a blind passageway, but they are there.  I would imagine the condensation issue is more prevalent on the xenon headlights which don't put out as much heat to drive off the moisture.

Bob