It would cost Porsche (or any other manufacturer) a fortune to remedy every small rust area on cars exposed to salt. The only way to prevent that is buyer PPI or personal inspection on a lift. Personally, I hate cars that have been salted because it's like ringing a bell, there is no un-ringing it, it's in the body panels and down the window frames too. It doesn't look like a lot of time in the salt for what that's worth. Be advised, lower your expectations of dealers being reasonable or not trying to gouge you because almost every single one will.