Buick Lucerne Engine Performance Problems Due to Crankshaft Position Sensor Failure

Engine quit 4 times over a period of 2 months. 2 Buick dealers could not duplicate the problem and even drove the car (1st dealer 7 miles, 2nd dealer 90 miles). The 4th time it failed we returned the car to the 2nd dealer and again they could not duplicate the problem. The car computer did not reveal any error codes (so the dealer said) and as the tech was driving the car from the service bay to the parking area it actually died on him, with no restarting. So somehow they did more troubleshooting and traced it to a failed crankshaft position sensor. Dealer will keep car 2 more days and drive it to make sure? they have it fixed. I had to work with a Buick customer service person in Detroit to get the dealer to continue troubleshooting. The worst part of the engine quitting is that the power steering doesn't work and it becomes more and more difficult to turn the wheel as the car slows. Luckily my wife was in the slow lane of the freeway going about 60 MPH the first time the engine died and our son sitting in the passenger seat helped her steer the car to the shoulder of the freeway. If someone is going around a mountain road and cannot steer into or out of a curve, over the cliff they go - my wife won't drive the car now because of this safety issue even though the dealer may have fixed the problem...we will see. We had a 1994 Buick LeSabre with identical problem and finally had to donate the car.