I have a 2010 as well and when I logged on I saw your topic and decided to look under mine, there is minimal rust under mine. Not nearly as much as in your photos. It is not normal, especially for a 2010. However it is normal for gm trucks. If you are leasing it don't worry too much but if you are buying it then you may want to see what they can do about it. I'm dissapointed about mine but I stopped worrying so much because I am going to try to get out of this vehicle as soon as I can. But financially I cannot afford it so I will be some time for me to get into another vehicle.