Are you even allowed to do something like this? My understanding is that every car in Germany goes through TUV inspection every 2 years and any modification from stock needs to be from a certified company made for you vehicle.
I can't see TUV allowing you to replace the front brakes with hub motors or substantially increase the front track with spacers. I also don't see a way to put in an axle shaft for an inboard motor on the front suspension
However, the De Dion rear suspension has promise
If I was adding an electric motor to a Smart I would mount the electric motor to the De Dion tube inboard of the green arrow. Then mount a sprocket on the rear drive axle and connect the two with a motorcycle chain.
