The average cost of labor per hour for an automotive technician in my area is $90 an hour.
For your employer to keep you happy and productive, if you ask for a pay increase.. he will just raise the labor rate to compensate and what he charges for parts, and also passes on a recycling fee for the waste oil. coolant and such.
Your clients expect the same services, whether it be something as simple as an oil change or complete motor rebuild.
So.. how is that any different from municipalities? Even if they downsize personnel, the citizens expect the same level or service... or is that "unsustainable", too?