There are at least two Special Airworthiness Information Bulletins (SAIB), CE-11-13 and CE-11-12R1, saying the aircraft has the potential for corrosion on the wing front spar at the fuselage attach fitting. One warns of the potential for corrosion on the wing rear spar at the fuselage attach fitting. The SAIBs mention the increased risk associated with high moisture and salt water.
https://www.avweb.com/eletter/archiv...t=email#230590
If you look here (on the main y'tube site) you will see a number of videos dealing with different SAIB's addressing corrosion on the -28.