Well it's been solved at last, despite me taking the car in ages ago to get balancing and alignment checked and sorted it turned out to be..... Balancing and alignment. One wheel was 60g out the other was 40g and the alignnent was set to 0deg on one front wheel and the other at 6deg toe in. Mate of mine has sorted the balancing and tidied up the alignment. It will need doing properly at the end of the month but it now drives a million times better A certain local tyre place will be getting a strongly worded call in the morning.