How can we trigger toast for 8 seconds using car-ui-lib

Hi, I am working on Android Automotive OS and I wanted to display toast with duration 8 seconds using the document https://developer.android.com/design/ui/cars/guides/components/toast

I have few questions:
1-) Where is the 8 seconds duration limit is defined?
2-) Do we need to only add car-ui-lib into third party apps and trigger the toast using - Toast.makeText() and it will trigger toast from car-ui-lib with duration 8 seconds?
3-)What is CarToast? Do we need to trigger toast using CarToast instead of Toast.makeText()?