Like most owners I have been concerned about the same problem. What I have done is to not wash the car too frequently. I place a tarp over it in the garage when not driving it. The amount of dust and pollen in the air is amazing here in Michigan. When I do wash my car I pull out the seals along the bottom of both doors to let the water run out. I leave it that way over night to make sure everything drys out. I then snap the seals back into place. It is easy enough to do. Along with the other suggestions to apply a rust inhibiting paint should be enough to protect this car.

Dennis