Rust issues Where in the U.S.

I would like to check out your avatar from the bottom up.......

 

MN/WI/IA/SD/ND have some of the most shit cars still driving on the roads.

When I get out of the Midwest I'm amazed at how clean older vehicles are. A 10 yo car in MN is usually destroyed.

 

I tried to get a car to rust..

But it dried too quick..dammit..

 

I've been wondering for the longest time, (and have yet to find a real answer and not an opinion)... How far inland do you have to be from the coast to be safe from salt air? I ask because I have been wanting to move closer to the coast but have been on the fence about it for a while now due to seeing the upkeep that everything near the ocean requires.