Working on cars is one thing...it can be fun and challenging. Knowing how to fix your own cars is a valuable talent....gosh you may get to work on your GFs car when it breaks down. However, working on cars for a living gets to be an awful drag.
Things aren't the same with cars as in the past. They are way more complicated...you wouldn't believe how much. Keeping up-to-date is a time-consuming job. It's much like being in school and having home-work all the time.
Then we get to the size thing. Cars are getting smaller and smaller....parts are crammed together more and more. A normal-sized American male is already having trouble. If you are a large person....say over two hundred pounds, you'll have many situations where you just don't fit.
Then there's the electric thing. If you're not 100% on electronics, on computers, on wiring and related electronic trouble-shooting, you are SOL. Some mechanics, even with training, are never good at this. New cars are filled with strange new electronic controls....more every day.
Then there's the new attitude management has toward their mechanics....you are the lowest rung on the ladder. Some shops, dealerships will treat you as such. They all wish they didn't need mechanics. You will be treated like a POS in those shops. There's hardly ever any room for advancement.
In the whole company you will be the only person required to purchase and own your tools. A mechanic these days can easily have over 30k$ invested in tools and related stuff. They may give you a tool allowance....usually less than 800$ a year.
Then there's the health thing. It's bad. Dangerous chemicals, worn equiptment, heavy lifting, fire dangers from gasoline, loud noise all the time, sharp metal pieces that get in your eyes. Inside the car you get cut on sharp edges, you're forced to get in filthy, horrible cars where it looks like you'll catch something....not kidding on this.
I could go on....It's always rated as one of the most dangerous occupations. Don't do it.