What yanks my chain is "menu pricing" that some dealers operate.
This is basically car X, costs £X for its first service and car Y cost £Y.
I took two company cars to the dealers for a service, and when I got the bill, one was £20 more than the other. When I questioned this, I was told that it was due to the cars being different.
I then proceeded to pint out both cars have exactly the same engine, same oil, same filters, same sump plugs, chassis etc, the only difference is that one is a different shape.
I asked how they had come up with two different prices (although I could see what they had done). They simply take the cheapest menu price and apply it to the smallest car with that same engine, and for any larger cars that have that same engine, they simply add X onto the price of the oil until reaching the set menu price. Hey presto, look at the invoice and I see that the oil is £20 more expensive in the larger car (yet it has the same part number stamped next to it).
I spoke to the regional manager, got my £20 back on principal, and they have never, and will never, see any of my companies cars again.