hmmm, this is a little tough huh?? is the dealer gonna warranty any of this for you? seems like it is a little rusty for a 2005 model. i have an 04 and nowhere near the amount of rust. so that makes me think it want taken care of, but that is just my opinion. i would take it back to them and tell them to fix it since they have to do certain safety inspections and or check before they can sell the truck. sounds like it is pretty unsafe to me. be careful. you are on the right track though by going through the hardware underneath and making sure it is all tight and secure. Good luck.
