Customer Service is crap anywhere in this country. Personally I wold take the free gas or oil change. Yeah, you might cost the dealership or sales person money, but you won't change how they treat people.
Customer service is crap because the only people willing to do it work for peanuts, and the car dealership is no different. No one wants to go to work everyday and be called a crook, or thief, or be berated because something sold in their store breaks, they didn't build it.Some how customers think they can treat retail people like crap and thats ok, but if they don't bow to the customer then they are rude. The basic problem comes down to respect, treat everyone politely.
If the salesperson is being rude/dishonest or the dealership does things you disagree with leave, not giving them your business is far better than hitting them on a survey. That would apply to anywhere you shop. I haven't shopped at Walmart or Sam's Club in 3 years because of how they treat workers/customers and how they drag the American way of life down in order to hock their cheap crap made in China. Lowest price is not the best deal.