Mechanic charges

Now I know many of you DIY (Do It Yourself) repairs on vehicles like I normally do, but when traveling, I do not like to carry heavy tools. So, when I took a 6 hour drive to the big city I had a reminder of the importance of how they charge. To estimate, they use a book rate to determine the labor cost. But the dirty trick is to charge you for each labor that overlaps the same labor for another job. When my water pump went out they were going to charge me for the book rate on the water pump replacement, belts replacement, thermostat replacement, and hoses replacement. When I caught this I explained to the manager that the car was not even in the shop for the total labor time on the estimate as well as that the time in replacing the water pump included time to replace belts, and shroud over the hoses. After, bringing this up, the manager took off the extra labor charges and took 10% off the bill which reduced the bill by $300!