Ah yes. A picture is worth a thousand words.
Looks like condensation on the front light. So let me see if I have this straight:
1) You had both rear light assemblies replaced
2) You also had both front light assemblies replaced
3) All of the assemblies which were replaced now show condensation inside.
I'm going to guess that it was probably warmer when you had the lights replaced. Warm air holds more moisture than cold air, and the air trapped inside the assemblies is relatively moist. Now that it's cold, the moisture is condensing on the glass.
Or, if the lights were replaced during a rainstorm (literally the car was being rained on while the work was going on) , that could cause the problem as well.
What you need to do is warm up the insides of the assemblies and circulate some warm air inside. That will evaporate the moisture and clear up the condensation. What I would do is borrow a hair dryer or heat gun. Remove the bulbs from the rear lights, and blow hot air inside (careful not to melt anything!) for about 10 or 15 minutes on each light. That should evaporate the moisture and clear up the fogging.
For the front, it looks a little more involved. I can't tell if it would be possible for you to use a heat gun, but the good news is the lights themselves might provide enough heat to eventually clear out the moisture. One thing you can try is wait for a dry time and drive for a while with the headlights on. Then find a mountain and drive up it (that will draw the air out of the housing as you gain altitude).
For what it's worth, that's what I think. One of the experts here might want to chime in also.
In any case once it warms up you should see the condensation disappear.
