Steering Noise problems of the 2012 Ford Mustang

I am writing this because it is related to safety issue and Ford does not reply properly to my questions. I am asking if my 2012 Mustang steering making loud noise constantly during turning, is it possible to be driven or have to be parked. Is it possible that steering will be stuck or not with the current issue? if the steering is stuck during operating, terrible accident will be happen. Fords should have a good advice on this problem since they make the car. I paid the dealership $120 to diagnose the problem that they already know. In addition, they charge $1800 to replace the steering unit. It is too much for a car with 48,000 miles. Ford recalls the steering unit on 2015 Ford Mustang, why not 2012 model? apparently, so many steering problems with Mustang in early state, and they are not cheap to repair.