Welcome! 
By coincidence, the rear drive unit (motor and transaxle) of the Mitsubishi Outlander PHEV that you are driving might be a reasonable choice (salvaged from someone else's Outlander, of course) to power the Mini. Even the Outlander PHEV battery modules might be usable.
By coincidence, the rear drive unit (motor and transaxle) of the Mitsubishi Outlander PHEV that you are driving might be a reasonable choice (salvaged from someone else's Outlander, of course) to power the Mini. Even the Outlander PHEV battery modules might be usable.