My driver's side headlight has moisture developing rather quickly inside the lens. I did replace the parking light/turn signal a while back. What is the fix for this, new lens? Just curious if anyone knows of an easier fix out there?

 

water test the seals, this does not usually happen.

Dry it out with some alcohol/water mix. requires removal.

 

Moisture building in the lights means an air leak somewhere.
You said you replaced the parking light?
If this is on the 01 in your sig then the headlight and parking light is all one assembly.

The glass might not be 100% sealed somewhere.

On the older cars when this happened we drilled small holes under the headlight where you would not normally see them. That would stop the moisture from building up in there.

Some newer headlights have vents in them which is supposed to stop it as well but does not always work.