Coolant leaks from passenger side? (driver side in UK !!)

mine did this. M103 engine.

Everything is now sorted, after a new head gasket and radiator........

The head was slightly warped, pressurising the coolant system so much that when it was cold it'd blow into the overflow tank behind the wheel arch liner past the 120 deg C coolant expansion tank cap.

This is worst case obviously, but get it looked into before you knack your engines.