Planar Reflection - using to create mirror

Ok so admit after watching a few tutorials and reading the online documentation I have more questions than before.

  1. So if you’ve already created a perfectly shiny material (100# Metallic, 0 Roughness) what additionally does using a Planar reflection object add if you are trying to recreate a mirror?

  2. In the Details there is both Planar Reflection Component and Scene Component categories. Didn’t seem to see this in the documentation nor was it mentioned in any tutorial I watched. Can someone explain?

  3. I’m simply trying to create a side view mirror(see attached). I’ve added a Planar Reflection component as a child to the mirrored material object but cannot see any difference (in the mirrored material) if I enable or disable. Is this the correct approach?

Thanks for any feedback!

So apparently not necessary if you are using Raytraced reflections.