2010 Sierra now has 3500 miles on it. It has tiny rust spots all over the sides of the truck. Have been working with the dealers body shop foreman. Today the body shop tried an acid wash to neutralize the rust spots. It did not work. The shop foreman said he will contact GM to see what the next step is. I've heard the GM excuses (thru my dealer) from the tech service department. Rail dust etc. Don't really care what the excuse is. If I wanted a rusty truck I would have bought used. I am pleased with the way my dealership has approached this, so far. Since I'm disgusted with this vehicle there are a couple other things I don't like. The new 6 speed auto trans shifts into 5th gear when cruising around town at 30 mph. And apparently the Active Fuel Mgt shuts down 4 cyls at the same time. I am very unhappy with this truck. Even if they gave me back $10,000 dollars of my $30,000 dollar investment I don't like this truck. $10,000 is what I could have saved buying the same truck used. I am very disgusted with GM. Thanks for the brand new rusty truck.