Is this okay? Or Rusty?

Hello Tundra owners,
I'm shopping for a used Tundra and found this 2016 with 49k miles. I'm concerned about rust. The CARFAX does not show where it was owned before 48k miles for some reason. The first line in History is at 48K miles in South Bend, Washington... (not sure why).

The dealer did an inspection and sent me these photos of the underside. Does this look like rust at all?
Another clue is: the brake rotors were replaced at just 49k miles. Aren't they replaced early if driven on salted highways?



Also, what is that flappy sheet of metal (looks like foil) in the picture above?
Thanks, Jon

 

Looks pretty clean to me.
I actually have a plastic skid plate just below that silver shield. The silver shield just looks beat up in comparison and looks like a bolt with a washer is missing at that lower hole.
Looking at mine I have one there, but it might be a connection to that skid plate I have.

 

Ok