The frames make up the “tree”, all spray-painted green.
The tires are (clearly) multicolored to look like bulbs and lights.
The entire tree is over 23 ft tall.
The tree can be seen in the Sydney district known as “The Rocks”, a tourist-friendly art and shopping district. “The Rocks” has been displaying Green Christmas Trees since 2008.
Some of the past trees:
2009: Plastic Bottle Christmas Tree
2008 Chair Christmas Tree