With long doors, the 2007 BMW 3 Series Coupe’s B-pillars, upon which the front seatbelts are fixed, are located quite far back, making for a long and awkward reach for shorter drivers. Since engineers were not interested in incorporating the belts into the seatbacks, the solution was to use an electronic extension that automatically brings the belts within reach when the car is turned on. They then retract back into the rear side panel.