Auto Completion For Custom Search Engines In Chrome

If we have to search for a video on YouTube or a product on Amazon, we will open up that site first and then we will search for it.
To avoid this, Chrome allows us to search using custom search engines without visiting the site first. In chrome search settings, we can assign a single letter to a custom search engine.
Now if we go to browser, type y and hit Tab, it prompts for YouTube search instead of default search.
This is handy. But the major problem with this approach is there won't be autocompletion in chrome address bar.
This is where vimium comes into picture. Vimium provides auto completion for custom search engines.
You can install it from chrome webstore. Once it is installed, go to Vimium options and add youtube search to custom search engines.

y: Youtube
Also add a custom key map for this search.

map y Vomnibar.activateInNewTab keyword=y
If we just press y, it open youtube custom search with autocompletion.
Now in every page, we have autocompletion for custom search engines.