Challenger SRT Demon
You were correct coming out at windshield both the same 50 degrees below at vents I now have drivers 70 and passenger 50. I would hope that they checked and know this holy crap. They checked the blend doors and all came back good.That's a completely different engine layout not to mention the other variables I mentioned so I wouldn't be too concerned about that being colder. Could be a faulty cabin air temperature sensor.
I'm assuming they tested with a thermometer, did they test it coming out of the windshield? Was it the cooler temp or the warmer temp? If it was the cooler temp then I'd guess it would be a sensor or blend motor not functioning properly. I wonder if they tested the temp coming out of the footwells too.