Today rear heater matrix plastic connection snapped. A month ago I posted on here asking if the plastic was prone to failure and Northern Bongolow replied yes.

why didn't I change it straight away. Luckily on a rough farm track just opening a gate when it failed. Alarm sounded an could see coolant running. Only a few hundred meters to work so no overheating issues.
Tempory U piece put between both pipes that go to rear matrix (as someone else on here has done) but had to call for antifreeze and wife to do a full bleed of system.
Think I shall now order a new rear heater matrix.