I'm sure you guys are right about the aircon, but I don't really think I have much of an argument with Mercedes at the moment - according to them they found the problem and fixed it under warranty.
I suppose I could go elsewhere to check the problem out, but to be honest, I'm trying to kick my dad into putting an order in for a 2006 S-Class (petrol this time I hope)!!!
Just hope these are built like they were in the good ol' days! Just imagine buying a W126 brand new and having the aircon break, and the fuel system spring a leak in year 1?!!?!?!?