alright mate, the best advice in the world i can give you is change the heater matrix and get some new pipes to it, without valves. last year i went to the VW meet at oldbry toys r us ( think its tomorrow night mate get down there, every 3rd wednesday of the month ) and it was colder inside the car then out.
since then apart from the engine being changed, i put a new matrix and pipes and changed the coolant, i have to turn the heater down now, its like a mini heatwave in my golf
