Hi when my Skoda Yeti was still new to me at least, it was due a service with the dealer and I said I could not understand why the rear window wiper sometimes worked and not at other times. He said that would be £90 to do the investigation, I though it was just in guarantee we argued and I left it with them.
Came back to pick it up when MoT done and and looked at bill no charge on it for the investigation. I was now talking to a different quite friendly guy, I mentioned the wiper problem, and he said that is a common thing you have to make sure the tailgate is closed properly to connect up the wiper controls.
I am afraid I shall be going elsewhere for future servicing.
regards
Roy