I should have known that contributing to this thread would be like saying to God: "come and have a go then if you think you're hard enough"!
After my ZS took the family and I down to Bournemouth and back over the weekend (without incident) I decided to treat it to a good clean. It had got pretty dusty, and a blowing boost hose had left some oily gunk around the intercooler and spattered about the engine bay. So I gave it a thorough jetwash and must have poked my lance somewhere naughty, because now I have a constantly lit green snowflake on the dashboard!
I've noticed this snowflake before - in the handbook it says it's for snow mode on 2.0 petrol auto models, but previously it's just come on as a check-light for a few seconds at about the same time as the coolant level light, then gone off again. Now it stays on constantly. Anyone got any idea how to get rid of it, short of removing the bulb?