2002 VW Passat was driving like a Honda Civic. Taken to the dealer, their mechanic saw a "voluntary recall" of the ignition coils and replaced 2 of the 4.
7 days later the car is back at my regular mechanics who says the other 2 are bad also. Regular mechanic thinks dealer mechanic should have replaced all 4 at the same time - "It's like spark plugs. If one goes bad, you don't just replace that one. You replace them all."
When I confronted the dealer mechanic, he said that you only replace the bad ones and stands by his decision to send my car home with only 2 new ones.
Who is right?