Joseph Meehan writes:

When a car is driven into a garage wet, the garage tends
to hold in the moisture for an extended period so often even on a nice
warm dry day the inside of a garage is still damp as the dry air can
not remove the moisture.

Come on. We're talking about outdoors, soggy wet with dew nearly every
night, vs a garage, perhaps more or less humid, but rarely condensing.

Again however I would caution anyone from reading too much into
this
part of the issue. I don't believe the difference between garage or
not garage is a major corrosion issue with cars. When it is a
noticeable factor, I believe it may go either way. There are just too
many individual differences to draw any certain conclusions.

Park your car outside, it gets wet through-and-through by condensing
vapor intrusion nearly every night. That's murder for corrosion.

I've lived with and without garages for a while. No doubt in my mind of
the value of garaging.