reportedly tested at least three different kinetic energy recovery system (KERS) configurations on its Formula One cars during 2008 and was dissatisfied with all of them. The most unusual setup involved mounting the batteries in the nose of the car. From a weight distribution standpoint, this was considered the most desirable approach. Unfortunately, this layout caused problems and required running the high voltage wires alongside the cockpit. The front-mounted battery also caused issues with the front wing which is critical to the performance of modern F1 cars.
A system that was developed with Magnetti Marelli had technical problems and a third different configuration simply didn't provide the required performance benefit. Ferrari engineers also encountered one of the big problems that engineers on road-going hybrid
systems have to deal with: learning to blend friction and regenerative braking. This is no easy task on road cars and, given the performance required of these race cars, it must be particularly difficult.
[Source: World Car Fans