Closed loop speed mode for electric vehicle

Hi,
I'm attending to a competition about efficiency and  I want to use roboteq motor controller with my electric vehicle. 
In-vehicle, there are two electric hub motors connected to rear wheels of the vehicle. But this configuration has a problem, for example when a cornering vehicle, the speed of wheels must be different so for this reason I've to control the motors speed accurately.
About my question,I have two KBL1660 motor drivers and one throttle (like car gas pedal ) all system is running over CANopen I  don't know about scripting, and ı don't wanna use that.

when I push the throttle I'll send an rpm command but I release the throttle What'll I do ???? I think, I  have three options;
1--    I can give 0 rpm command but this way controller will try to current rpm set to 0 with desired deceleration ramp but this is sooo wrong !! for this setup. 
2--    I can make the wheel free rolling and I hit the hydraulic brake pedal as much as I need. But I didn't find a way to free-rolling the motors except emergency button but again also this is sooo wrong !!!.
3--    I think this is the best and healthy way, when I release the throttle if I can manage to activate regeneration over CANBUS that would be a great solution for this kind of setup. And  I don't even use a hydraulic brake pedal so  I can drive a single pedal such as a production electric vehicle.

and there is an explanation for electric vehicle in the roboteq user manual but I don't use torque mode I need closed-loop speed mode.;
  "Torque mode is mostly used in electric vehicles since applying a higher command gives more “push”, similarly to how a gas engine would respond to stepping on a pedal. Likewise, releasing the throttle will cause the controller to adjust the power output so that the zero amps flow through the motor. In this case, the motor will coast and it will take a negative command (i.e. negative amps) to brake the motor to a full stop."


Any suggestions and help are very appreciated......:)))