On the topic of utilizing your time making money VS working on your own car, I'm going to leave my favorite quote:
(Disclaimer: If you only have 1 car as a daily driver, totally understand needing to rely on the mechanic. We've all been there. But, you should aim, as a man, for a slightly higher degree of independence - especially with the way the world is going)
“A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.”
- Robert A. Heinlein
You can't always look through the lens of "how much is my time worth" when learning something. The skills, experiences, and things you learn about yourself as a man are priceless - and you might uncover a hidden passion/talent! Learn to do a small job the mechanic may have charged you a ton for, if not to do it all the time, but to better understand what is being done.
It reminds me of the parable of talents Matthew 25:14-30.
24 “Then he that had received the one talent came and said, ‘Lord, I knew thee, that thou art a hard man, reaping where thou hast not sown, and gathering where thou hast not strewed.
25 And I was afraid, and went and hid thy talent in the earth. Lo, there thou hast what is thine.’
26 His lord answered and said unto him, ‘Thou wicked and slothful servant, thou knewest that I reap where I sowed not, and gather where I have not strewed.
27 Thou ought therefore to have placed my money with the exchangers, and then at my coming I should have received mine own with interest.
28 Take therefore the talent from him, and give it unto him that hath ten talents.
29 For unto every one that hath shall be given, and he shall have abundance; but from him that hath not, shall be taken away even that which he hath.