How do I know if my car needs a polish?

Most people realize their car could use a polish when they park it next to a similar car of similar colour which is much newer. It is here but comparing old with new that the difference becomes obvious.

They might also see their car on a bright, sunny day and notice the cobwebs or swirl marks.  You can look for evidence of dull and dead paintwork, scratches and stains, and if you feel you would be happier if your car was really shiny, then you probably need a polish.