Anyone used the Bosch HEPA cabin filters? I got one due to the pollen and such but was just driving today in the 90Â° heat thinking my wife's car needed the fan up too high. I asked her if it was normal to need it that high and she didn't know. Anyway, is this bad for the fan motor or anything? Otherwise, the filtration is supposedly pretty good...just curious if I'm imagining less flow or if it's something known.