Beach Buggy Racing uses the PlayStation 4's system settings for "safe zone" or screen area.  To change this setting, you need to adjust the PS4 Display Settings.  Here's how:

  1. At the top of the main screen on your PS4, select "Settings"
  2. Select "Sound and Screen"
  3. Select "Display Area Settings"
  4. Use the arrows to adjust your screen size and hit X when you're done.
Now the game should adhere to the settings you've chosen.