to some aspect they do thru regenerative braking systems.
i have seen some videos posted on facebook they tow a completely dead tesla 1 mile it gave them a estimated 1 mile of driving charge.


from what i assume you are describing attaching a generator to the drive axles it would significantly reduce the driving distance due to drag from the generator.
i am no engineer but you are describing something like making a preputial motion machine that gets endless energy. they have been attempting to make one successfully for eternity.
i would assume it takes a bit more energy to make the electricity that the motor driven by the electricity.