Yeah, the matrix has defo gone, driving along happily when screen started to mist up and the lovely smell of anti-freeze entered the cabin, lifting the carpet on the passenger side revealed damp sound proofing and looking under the heater I could see drips.
Curiously I only lost about a pint of coolant, I had this heater core repaired about 5 years ago because one of the pipes had a crack in it-only took an hour to get out, but drying the carpets and sound proofing stuff took a lot longer!