A teenager has admitted to being behind the wheel of a speeding stolen car and causing a crash which killed three people on the Fraser Coast last year.

The boy, who cannot be named, was due to appear in person in the Childrens Court of Queensland on Tuesday morning, but he refused to travel to Brisbane from the detention centre.

Instead, he appeared via video link, and Judge Deborah Richards told him the defiant behaviour was "a pretty stupid thing to do".

Seems a bit of an understatement...