With hindsight this was inevitable. I knew the radiator wasn't in the greatest shape but it seemed to be working OK (with the transmission cooler bypassed anyway). Suitably plugged up it wasn't overheating or otherwise causing problems. In the back of my mind I knew it wasn't right since there was a leak to the cooler, but my optimistic self figured with the transmission lines suitably blocked it wouldn't cause a problem. Headed off Saturday morning to make the start line in Gunnedah for Sunday, only got 20km before the temperature hit 110 so pulled over and was confronted with this. Radiator has failed of course. It's comprehensively stuffed and I should never have put it in the car. Stupid me waited for it to stop hissing (went and grabbed a quick drink), figured it was cool enough to pop the radiator cap off and boy I was wrong. A glorious arc of coolant made a guyser out of the radiator and glopped on my head in a scalding splash. Lucky I haven't had a haircut in a while and didn't suffer any real injuries (don't be me!). Hiked to the service station, bought a couple of bottles of coolant and some radiator stop leak, yanked the thermostat and nursed it back home. Made the phone calls to tell the owners it had to be scratched from the event. Lucky I suppose it happened close to home rather than requiring a very expensive tow from Queensland. I am disappointed though - we nearly scratched it a few times and doing that earlier would have been more sensible. Maybe next year.