A nice little extension! Rated 5 out of 5 stars

Searchbar Autosizer simply allows the searchbar to expand wider. There are three major options for this extension, 1. to size the bar incrementally with each letter, 2. enlarge the searchbar on first keystroke, and 3. to keep the searchbar the same width all the time. For users who desire even more control there is an advanced option button for fine tweaking searchbar dimensions and movement. This small extension provides a simple yet needed and desired convenience.

This review is for a previous version of the add-on (1.3.5).