Originally Posted by mdaniels4
It's kind of interesting, that I was once told by a car paint guy that a build up of dirt in the winter, if you don't keep it washed all the time, is actually better for the car than a semi clean. the reason for this is that the dirt acts as a barrier to the salt and the moisture and therefore cuts down on the oxidation overall. The paint is alot tougher than you think, and too much washing lends itself to water staying in recesses and the like and hastening the rusting process. That's why heated garages in the winter, while more human pleasing is not all that good for the car, it keeps the water in liquid form while at the same time mixing with salt. Better to let it freeze dry and slowly evaporate. I take mine through the wash about once a week, and hope for the best.
As long as the salt "jacket" is dry, I wouldn't think it's doing that much damadge to your paint either. Any place you have a stone chip or an unsealed scratch, (where there's bare metal) that's a different story.
The biggest problem I see by not washing the dirt, salt, and road grime off your car is this. If somebody walks by your car and accidently brushes up against it, it's just like they're "scuffing" your paint with a piece of sand paper, thanks to the above mentioned dirt, salt, and road grime.
