Geoff your theory is somewhat accurate about the dissimilar metals but in the case of the liftgate it's not the actual problem. When the pieces ( liftgate and hood ) were painted at the factory there was an issue with the prepping and minor iron contaminants were left on the surface and painted over. As time goes by these metal particals react with the aluminum panels and cause the corrosion and bubbling of the paint. I don't believe the chrome piece on the liftgate is metal I think it's just chromed plastic, which is why this problem still affects the hood and areas of the liftgate not touching anything else.


Matt