How much should the car repairs cost?

How do car dealership controls trade in cost of repairs to max the profit on used car?

• As anybody who trade in car for new one. All dealership has new car and used on their lot to sell. Of course mark up is bigger on used car than new one. However the questions is how do service department work with sales service as fix up to sell? The service department always try to do many repair as possible to max the profit. Yet sales department try keep spending at minium to max the sale profit. So how they work together? It would cause conflict of interests for one department against another if they not following standard guidelines from their own department rules? Most dealers keep organization, budget, businesses and management separate even those it under same ownership. Sales department, Service department and parts department. They are three separate businesses under same dealer at same building.

• Answer:

  When they check the car out in the service dept. , they check it like its for inspection / emission. They send a quote to the sales department of the minimal work needed. Then they decide to fix it or send it to auction