A faulty key destroys my Smart Car alarm system. The cost of this is £370 to repair (mainly for door actuators, which are the bits that physically move the locks), but I can't put petrol in the car because the petrol cap is still locked as the actuator in this wasn't repaired (obviously they though my car would only need one more tank of petrol for the rest of it's life). So when I got the car serviced today I told the guy that I needed the actuator in the fuel cap replaced, he told me not to worry. When they give me the total for the service, I think it sounds high, so I look and see that they have charged me £45 to diagnose that......the actuator in the fuel cap needs replacing. They didn't replace it mind, just tried to charge me £45 for telling me what I had told them.
So we sort that out, with the help of a very nice customer care guy. This of course meant I wasn't closely following the next bit, which is when I get home, by boot won't shut properly and when I use the boot release button, it falls out of the dashboard. So another phonecall together.
Earlier this year I used a different Mercedes dealership to repair my windscreen wipers. When I got home it transpired they had forgotten to put my radiator grill back on (I didn't notice as it was parked up against a wall in the garage car park).
And these are the official (expensive) dealerships. Arghhhhhh!

A Smart car (not mine)