>Automotive repair is barely a moat, because you don't need that much training to work those jobs.

You need to study for 3 years to be a car mechanic. And even then you'll need baby sitting for a while in the auto-shop because no one trusts the new guy fresh out of school, with good reason.

>There's a lot of people who want to do it.

No there isn't. What do you mean by lot of people? Automotive repair is a blue collar job with intense physical strain, you're exposed to chemicals you shouldn't be, there will be hearing loss involved no matter how much protection you have and it doesn't even pay all that well, considering the risks involved and the amount of training you need. And no, it's not because the market is saturated with car mechanics, it's because auto repair shops have a lot of pressure to be cheap. Job listings are full of car mechanic openings, you'll never be unemployed.

All the "if's" presented are solved by relocation and not even that much of it, except for this:

>if fewer people are buying cars

Then the skills are easily transferable to other vehicles. But less people are buying cars already, they use uber, which involves a car. A car that needs 10x more repair time than the car you drive daily.

So yeah, auto repair is a good moat. It's complex, not everyone can do it, it's not licensed in most cases (unless you work for a brand or a niche) but there's reputation involved and it's always needed. It just doesn't pay all that well, specially not compared to what I see on HN's monthly whoshiring.