McLaren's 4-paddle steering wheel

[Kissyface]

It is believed that Renault have a similar system but haven't refined the technology enough to exploit it or perhaps it isn't that advantageous to begin with.

From my understanding it works like this: engine mapping can increase or decrease torque and so by modifying the engine torque on certain parts of a circuit wheelspin is reduced to increase grip on corner exit. For example, you could exit one corner in 3rd gear at 120 mph and 9500 rpm and exit a different corner in the same gear at the same speed at 8500 rpm. It's possible that these settings could be modified during the race to compensate for the changing handling characteristics based on factors such as fuel load and tire wear so the driver can achieve a more balanced performance by offsetting these changes with different engine torque settings. Setup then becomes key on the days leading up to a race where the driver has to run the car at different fuel loads so as to build a database of engine output on that particular circuit then the engineers can determine where the most advantage can be gained.
I will continue to research this and update my findings so at obtain the most accurate information.