Garaging during winter, no salt exposure — how long will extend car's life?

[nerp]

So far since getting my car, I've managed to avoid driving it in any snow condition and only when roads are completely dry in the winter, opting to use my wife's Forester on those occasions. It saves miles and keeps the car looking much cleaner all year long.

I recently bought a new home and it has a garage and I'm happy with the fact that I get to keep it parked out of the sun during the day and nice and dry whenever I'm home. It also means I'll be able to limit its exposure to winter roads even more since I won't have to clear snow from it, etc.

Anyway, for someone who lives in the Rust Belt like me (RI), how much more life am I giving my car by not exposing it to winter driving? Aside from the salt (not much used here actually, only major freeways/interstates) there's the grit and sand that gets everywhere and cuts up the paint, not to mention the temperature changes and moisture all over everything. Is it reasonable for me to expect adding a few more years before the paint becomes a major issue? I know that keeping it in the garage when there's snow on the ground makes sense, but how how long until I'm being overprotective and irrational? I don't want to not drive it if it really doesn't make a difference.

My hunch is that the biggest thing about garaging is avoiding all that UV exposure when the car sits parked outside. But will I be steering clear of any rust issues if I basically don't drive it except for dry sunny days with no melt puddles from Dec. to March?

 

[desy]

If your garage is heated it will cause a problem as with any chemical reaction heat is a catalyst. The frozen stuff will retard growth of rust over water and salt on freeze thaw cycles

 

[HarryLui]

I live in Phoenix, AZ and drove a 24 year old car to work this morning and it looks like this. We have no salt on the road nor snow.

The bottom looks like this.

 

[SparkyJJO]

If you want to avoid all salt-induced rust don't even drive it on sunny winter days as there is still salt on the roads that will get on the car.

I don't drive my car from the time the snow flies until at least March and after a few good rains to wash off the roads. It is a 99 and it is rust free.