Two roundabouts out from work I detected a whiff of coolant. By the time I joined the slow queue onto the business park the temperature gauge had nosed its way above normal. I steered into a convenient slip road just as the steam emerged from the side of the bonnet.
Split top radiator hose, less than a year old and bought from Martin Robey because the kit promised Kevlar reinforcement. Very disappointing performance. It's split like a rotten tomato.
Sat in the car proof-reading pages for Practical Classics until the engine cooled and the traffic queue had died down.
Borrowed the Porsche at lunchtime and went home for the old hose I replaced a year ago. It hadn't failed so I kept it – waste not want not, as we say in Yorkshire.