In version 2.14 of the plugin it's possible to use autocomplete on gotoaddres field, directions form etc.
See:

Here are some tips on changing autocomplete styling in general:

  • Add to your template css a section for autocomple and add a definitiion for the class pac-container:
    .pac-container {
    }
  • To change the color of the results, add to this definition:
    color:#000;
  • To change the width of the results, add to this definition:
    min-width:250px;

To change the individual items styling:

  • Add to your template css a section for autocomple and add a definitiion for the class pac-item:
    .pac-item {
    }
  • To change the color of the item, add to this definition:
    color:#CC0000;

Also read Google documentation about autocomplete styling.