Unfortunately unless you stand over the mechanic, you dont know what they are doing. Whem my wife took our Caravan in they told her it need all this work and was going to cost $550. When I showed up the next day, it mysteriously dropped to $350 for the same exact work. Their explanation, a misquote on parts. So I explained to them that was inpossible since the only part being replaced cost $50 -$75. In this day and age, I have learned my lesson and question everything and don't leave my vehicle with any dealer. We found a local mechanic that always gives us the best explanation and cheapest price. His customer service is above and beyond dealers and thats why I stick with him.