I did this very thing back in 1989. I was a line cook and had an Art Degree. As a hobby I would work on old VW's and taught myself a lot and rebuilt many engines. I ended up going to Auto School and getting a job at a VW Dealer at the same time. I basically swept floors to get myself in the door. Auto School definitely excellerated my certification level to a Master ASE technician and VW Master technician. Look into Auto programs at Community Colleges to find the best price. Trying to get in as a technician without some schooling could be tough but not impossible. Passing the ASE test certification could also be difficult without training as you learn theory in school. However, if you get into a dealership they may send you to their schools and you get some level of certification. It was a good career for a long time. Good luck!