While still browsing around trying to sort all the cooling bits ande bobs I came across VW GOLF 84-93 GENUINE EXPANSION TANK on eBay (end time 19-Mar-11 07:44:13 GMT)

What do you guys reckon??

Ah, yes. One of those limited edition expansion tanks that have a little pump to squirt water at things to make them expand...

And the winner is....

wow

obviously will defrost windows with the pressurised steam it will hold lol