Camp Lejeune for the most part. I also spent some time in 29 palms and Okinawa, Japan. And a deployment to Afghan.
Only mechanics I knew were for Motor T. So they worked on HMMWVs, 7-tons, and MRAPs mostly. For which they did not have the money to fix. A vast majority of the vehicles we have are out of commission and will be until there's another war to fund fixing them.
And nearly everyone in Motor T, mechanic or driver, is about as redneck as you can get.
As for other mechanics, no idea. I'm sure aircraft mechanic pays well in civilian world. Tread mechanics is probably to niche. Generator mechanics might be good also.