The French give instructions for three starter models with the Xtreme Power Motor set, and due to the limitations of parts supplied the third model needs improvement.
One area of concern is the fixing of the driving axle which is supported by two trunnions, one of which is secured by a single bolt and is potentially weak. Another issue is the motor/gearbox, which is again only secured by two bolts meaning the unit is not rigid.
My modified model uses very few extra parts and solves both issues well.
In my view, these sets are good value for money, but could be very much improved with more time spent on the development of the models.