I'm surprised it would make much a difference in a car where the air is being constantly circulated. I mean I can see it in a closet where the air is pretty stagnant but it's the opposite in a car. I've found in the winter what really helps is to frequently use a wet vac to suck out all the standing water from my weather tech floor mats as the snow melts, before doing that I was frequently getting foggy windows when I had standing water in the car.
2012 SL purchased used 2/'16
2013 S w/QC purchased new
Juicebox Premium 60a L1/L2 EVSE, Ebusbar 16a L1/L2 EVSE
'12 EVSEupgrade'd 20a L1/L2 EVSE, '13 EVSEupgrade'd adjustable 6-20a L2, 6-13a L1 EVSE
Zencar 13, 20, 30a L1/L2 portable EVSE
GE Durastation 30a