Sirius Glass
Subscriber
Thanks for this Folkloric analogy involving a notoriously known shady business (car repair); and mechanics, who are widely accepted as misleading, fraudulent and unscrupulous.
The car repair business has to be the #1 ranked shady business on the planet. And if you ask me, the camera repair business (especially involving Leica) is #2. As someone already said, the Leica pedantry and wannabeism is a very expensive hobby, and the involved repairmen are scrubbing their hands.
First of all go find a good mechanic and stick to him for regular service. I have been using the same mechanic for 35 years.