i had the same issue for the better part of 2 years on my 18... it was the results of a repair job failure. after some major hail damage and repairs done, which included removing and reinstalling my sunroof, i started having electrical issues and condensation buildup inside. they had crimped and punctured the drain hose from the sunroof on the drivers side. with full weathertech mats i had no clue what was going on except something was very wrong(nav center would go out, console items would turn themselves on and off, driveability was starting to be affected)... took a good mechanic who actually listened, removed my a pillar cover and poured water on my sunroof... which then poured directly onto my dash without the cover. that repair shop had to foot the bill for replacing my comp consoles, which were water damaged by that point. thankfully, no leaks since and she's all good. the same kind of effect can happen if those hoses get plugged.