Mad as tits on a fish.
Absurdist comedy horror as a tyre called Robert goes all Scanners on everyone's ass (or head, more accurately).
Why? It's explained right at the very beginning. No reason.
Some nice touches here and there: witness Robert's first attempt at tentative trundling (after literally rising from the dust like a vulcanised psychotic Adam), and shed a wry tear as it brings to mind Bambi learning to walk (or was that just me?); and the inter-textual witterings of a group of spectators have some nice lines.
Did I enjoy it? Hard to say. Worth a watch? Yeah. Worth a rewatch? Probably not.