I found some rust on the underbody of my car. Is this something I should be worried about?

What is the best way to remove it? I heard that wd-40 or naval gel combined with sandpaper or a steel brush should do the trick.

I attached the photos. Please tell me what you think!

 

Pfft. I wouldnt worry bout that! You should see under mine....effin canadian winters combined wirh road salt does not let cars look new for long!

 

Get a rust converting paint: http://www.eastwood.com/eastwood-rust-converter.html?srccode=ga110070&device=m&matchtype =e&network=g&creative=4104381840&gclid=CLDNraT0j7g CFdB7QgodvDoAog

 

I wouldn't worry about that. Just keep an eye on the exhaust flange at the muffler. They tend to rust out