My car is now back with my dealer so will post an update as soon as I have one. I tried to find a local tyre fitter who could check toe out but 3 wheelers aren't compatible with their ramps/computer based alignment rigs and nobody seems to have the old "dunlop sticks" anymore!!
Allon White have been very helpful and plan to check alignment first and then work through a diagnostic routine with the factory...I'll keep you all posted but won't be able to try the car again myself until Saturday