For anyone that is interested, I just looked at the spare wheel area. There is a PVC tyre cover, that is a neat fit around the standard 19inch bridgestone combination. Therefore, this cover will not fit over any tyre that is larger, and the Cooper ST is 20mm larger for the 245/70/17 and 40mm for the 265/70/17. I'm pretty sure the new wheel/tyre will still fit without the cover, so I am going to jump in and oder the tyres today. I think then what I will do, once I have the setup, is do some creative mod to the cover, so that it still at least protects from underneath, and from the front, assuming any bedri that may hit the tyre, will hit the front. I'll take some pics of the surgery if anyone is interested. I'm going the 265 tyre, and will get approx extra 20mm ground clearance, and I'm punting, based on the calc's I have done, that the speedo will just about be perfect.