Right, I sort of expected there to be an attribute for an url.

   <datalist json="search.php?q=toyota+corolla">

Static could be better too. When search engines first started building these auto complete dropdowns the multi word input was really the killer feature. To have something like "green toyota" you would have to generate an element for all color and brand combinations? And the you want it to work for "green toyota corolla" and you get an abc kind of list length.

Perhaps a wildcard would have been fun or regex options.

  <option value="* days"></option>
  <option value="* weeks"></option>
  <option value="* years"></option>