I used it years ago but only for small starters...the regular universal carboy bung fits. But since then I've learned that 1 qt. starters aren't really that
helpful (unless your starting with a small amount of yeast) and you'll get 40 lashes if you put an airlock on your starter.
It would be fine to fill up and take over to a friend's house or whatever as long as you keep it cold and drink it relatively soon...although it prob technically would be an 'open-container' in your vehicle.