The VW exec revealed that start-stop technology will be standard in a BlueMotion version of the new Golf and optional in other models in the new Golf family.
The stop-start system works by shutting the engine down when the car is stationary, such as in a traffic jam or at a red light. When the accelerator is pressed the engine starts again smoothly without needing to restart in the same way as it does when you turn the key for the first time. BlueMotion is a range of VW products that have been specifically optimized to be as environmentally friendly as possible.
Source: Motor Authority