frame rust

Got some pictures of a 2018 LC200 for sale in Montana, I got pictures of the frame and underbody. In some parts of the pictures I can see clean black frame but then other parts looks like they're covered in something. Is it protective coating or something bad like corrosion? I can't go see...

I bought a 2002 4wd Tacoma std cab, 2.7liter 4 cylinder with a 5 speed manual. I bought this online sight un-seen which is not the a recommended poll thing to do so I got screwed. The vehicle is great with the exception of the frame. I see some repairs and I see some rust perforation on the...