Ford Motor Company says it plans to add anti-rollover technology to its Explorer and three other sport utility vehicles for the 2005 model year. The Explorer has been the target of lawsuits that contend the vehicle is prone to roll over. Ford says it will add the new stability system to all versions of the Explorer, as well as the Mercury Mountaineer, Lincoln Aviator and the Lincoln Navigator. It will be optional on the 2005 Ford Expedition. The anti-rollover system activates automatically when the car begins to tilt, by slowing the engine and gently applying the brakes.