How much trust?

I always thought that the front pads did most of the work judging by the amount of brake dust on the front wheels and almost none on the rear.

So did I after doing my own maintenance (and for others) over many years ..... but I was mistaken to some degree. Our tow car is just that and used for holidays with the caravan and not a lot otherwise. The rear discs and pads are smaller than the front and are not far behind in wearing down.  

My daughter was told the water pump was leaking on her Ibiza according to the Seat main dealer and they wanted over £800 to replace it and fit new belts. I had it checked by a mechanic I use he told her there was nothing wrong with it, That was 5 years ago and still no leaks.   

They could replace them for £259.  If only 60% worn, what about the other 40%?

Sounds a little high, but hard to judge because, depending on vehicle, brake pad prices and degree of work involved can vary significantly.

Regarding wear thickness, as the friction pads get thinner the amount of heat transfer through the metal part of the pads, and into the cylinder assemblies themselves, becomes greater.  Allowing them to get too thin does run the risk of the rubber seals becoming damaged by too much heat, and then it means either cylinder assembly overhaul or new assemblies.  When I did my own maintenance work, I used to change the pads at between 60% and 75% wear.  The increase in cost due to eary change of the pads was, IMHO, more than offset by the cylinder assemblies themselves not deteriorating.

We get a video of the inspection e mailed and this shows the condition of the brakes so we know the truth. One firm I know of always finds something wrong so I would avoid them.

I am always offered air con work and other things, but if the maker does not require it then it is not done.

I left because so many so called mechanics were robbing barstewards that charged for work not needed, or simply didn't do what they charged for. Most couldn't change a wheel. Then there is the £139 for a re-gas? really? When a mobile air con guy will do it for £45 AND come to YOU? A blatant rip off.

Air con should be used all the time, not just when it is hot outside. Air con keeps the car free of steamed up windows when it is cold and/raining, not just for keeping cool in the Summer. All you need to do is turn on the air con and turn the temperature up if the weather is cold. It also stops the seals from becoming brittle.