Lets us know what comes of the call, Im not suprised previous problems or niggles wheren't brought to your attention after all they are looking to get your money, they are a car sales business but after care is also a big part of their business too sadly some dealers do the second bit better than others.
You could have bought a £30k second hand Merc and had the same problems, also Id (personally) take the 200 spot check with a pinch of salt, if it starts, stops, isnt sitting in a puddle of something, isnt rattling like a old tin can and hasnt got any trim hanging off Id be suprised if some cars are checked any further.
Out of interest, is it worth people (including myself) asking the next time your car is in for a service/inspection etc to ask if the casing of the gearbox is dry?