My best friend is an ESTP and he's worked as a mechanic. The best mechanic I know is an INFJ. I'm in awe of him, honestly.
I think the best mechanics have a sense of organization. Regardless of type. There is natural aptitude in mechanics but all that is worthless if you aren't thorough in the details. I've seen people who are naturals yet they mess things up because they're too impatient or want to take short cuts. It baffles me.
They end up messing the job up over the easiest stuff. I've had to fix some of their problems so I know. They are great at diagnosis but crap at implementing the solution.
Point blank: If you can think in a linear manner, are good at understanding principles, cause and effect and applying that to real life scenarios, follow directions and be thorough then you can be a pretty decent mechanic.