I don't think you are paranoid at all. I had a different heater problem, for me the heater was on all the time,and it took my dealer nearly 6 months to fix it.Kevin t said:
It seems to me that modern mechanics in main dealer workshops are generally incapable of doing anything unless their computer spews out a fault code and tells them which part to replace. They just don't seem to understand how modern cars work and are totally dependent on their diagnostic computers.