Hi Rocket, the standard super S alloys are 13" diameter and 5" wide. The recommended tyre size is 175/60 R13. I reckon it would be really counter-productive to fit a tyre that is any wider without a wider rim.
Yes, i recently had some Yoko A539 fitted.
I have only had these on for around two months so I am not yet able to comment on their life-span etc. However, I have to say I have found they are simply an awesome tyre for grip and performance in both wet & dry conditions !. In the wet they are fanastic, hardly notice the road is wet !.
They cost around $120 each. I had been using Falkens for many years which I was happy with but I will be sticking with these Yokohamas from now on i think !.
Yes, one tyre place told me the A539 is no longer being made (replaced by the C: drive which doesn't come in a micra size) but you still seem to be able to get them.