I wonder if this 53 gear old auto technician can retrain for this field.
No. Even if you could no one would hire you at that age.
You can retrain, but the guy whose job is standardized and the same thing every day for months or years, his job will be eliminated.
According to the FBI, car hacking is a real risk.
Of course, these days, the FBI is in bad odor, due to its execrable Director.
But it's nevertheless the case that cars are becoming more and more computerized, even to the point of becoming self-driving.
You need to make yourself the go-to guy for automotive automation.
“I wonder if this 53 gear old auto technician can retrain for this field.”
If you can fix things, you can learn to fix robotic machinery as well. Cars themselves have been becoming robots over time anyway - a sensor there, a computer here. Some are already on public streets driving themselves.
If you are enterprising, you can keep up with the new equipment as it comes out.
At some point though (10-20 years), robots will become the mechanics. So sock away a good piece of every paycheck into long term investments (like ETFs, real estate, or a side business).
Early on, while mechanic robots are more specialized, you could buy some robots and operate your own repair service. Eventually though, cars and robots themselves will likely be built to be serviced by general purpose robots, with a minimum of special tools - so anyone with a general purpose robot will be able to download the mechanic software and fix their own equipment.
Just like people with a smart phone download apps to make it replace another item (GPS, stopwatch, TV, radio, flashlight, etc.), owners of general purpose robots will be able to do all kinds of things with them. Once a machine has the general strength, dexterity, sensitivity and mobility of a person; the rest is just a software update. Then one household robot will be able to do many jobs - plumber, doctor, chef, dog walker, baby-sitter, landscaper, fruit picker, security guard - mostly anything people can do. That is when most of the old jobs will go away en masse.
So either save up enough while working as a mechanic, or start your own business (or a few businesses). Small business owners will be able to do a lot more with their robots as well. There is still time for you - probably for all of us.