If I may elaborate a bit. For every hourly wage a person makes add 15% the employer has to pay to the IRS on the 15th of the month for every employee, add the liability rate to that for the work being done, each activity has a rate it charges per 100 dollars of payroll. Then the same holds true for workmens comp all requirements of being a employer and that is before any other overhead. Payroll tax 15% comp rate for say roofing is another 40% depending on where you are for comp then add the liability rate probably about 18% anything where feet leave the ground is pricey but other industries have thier own high risk activities. Some states have paid family leave policies you have to buy. That is before you pay any other overhead. We are very blessed to have a few very good mechanics around us. I want to tell them to build a vehicle for mass production because the market of the big 3 is a mess after the EV push..
You allude to the societal belief that the charges for auto repair work go directly into the mechanic's pocket, and that the mechanic is laughing all the way to the bank, by most folk.
I appreciate your listing those "holes" in the coffers of an auto shop. Add this to the mix: When you bring your car to my shop, I charge you xx dollars per hour in labor. I also charge a mark up on parts, a modicum for shop supplies, and a disposal fee for fluids. which are hazardous material, for which, I'm liable and beholden to the EPA in the event of a spill.
Next: So, that new fuel pump I charged you 1200 dollars total for replacing takes a proverbial dump 2 months after I replace it. Now, I get to have the car towed (my expense) diagnose the problem (my expense), and tie up a lift/stall for maybe up to 2 days and NOT worked for profit on someone else's car (again, MY expense).
This is called warranty overhead/cost.
The bills don't stop, but income does AND I get to work FREE for up to a couple of days, in some instances.
So, average it all out! When all the liabilities and headaches are dealt with, There's no way My shop makes NEARLY what average folks might think!