PS - The Toyota iQ has the same engine, but mounts it differently to save even more space - the engine centre is behind the front axle - does this make it mid-engined ?
So on a search I found this which includes a wheel profile and measurements :
from here
Toyota iQ: six degrees of innovation – No1
As you can see the iQ mount is also slightly tilted to save space. If you follow the link there are also details on the differential which is, er, different from conventional types, as well as other space saving stuff such as a compact AC unit, centre take off steering etc.
For reference the iQ I think has 15 inch wheels. Again there is one round the corner from where I work and I have chatted to the owner before, he may let me take some pics.
I'll still take pics and measurements of George's more conventional mounting if you need them.