Cheers for the info guys... Hmmm, gonna get to the bottom of this tomorrow. I've had one on the back already so know they fit, logically the fronts should too, yes?
To be honest, the centre bore on the new ones is only briefly 5.6cm, it tapers away inside the wheel, so should be alright I think?
Just to check, the Micra is hub-centric yes? My wheels are lug centric... Imagine theres an adapter I'll need then?