Well chaps I decided to bite the bullet and get a set of winter tyres. I bought Falkens from an online seller, think it was e Tyres but would have to check. What a good move it was as well. Had them fitted last weekend and it has completely transformed the car. It may be part due to having full tread depth, but in the wet ( of which we have had a tad lately ) there is far less understeer and little or no aquaplaning. I drive the same way home every day and there is a piece of road holds water and before there was a bit of movement now there is none. Braking is vastly improved also so well happy. Whether it will turn the Merc into a "normal" car in the snow is yet to be seen .If anyone wants more details I will hunt the bill out but I did a bit of research on the tyres and they stood up well against more expensive tyres and at only £98 each didn't break the bank.