im pretty sure mini wheels are 4 x 101.8 so you could use wobble bolts which some people swear by and have no problems with but i dont think i would ever use them. You could always get the wheels re-drilled which as long as its done by a REAL engineer and then balanced properly you should be fine.
If your interested I have a picture of when my micra had 13s on the front and 15s on the back, but also my back is raised by a couple of inches from standard. so basically what your looing for.
I tried to host the picture on here but its too big. add me to msn and I will send it you.