Hi there - and welcome to the forum.

Can your son help at all with looking for jobs? Since he's there, he'd have better access to local sources for job adverts. I'm assuming that your husband speaks enough Spanish to be able to cope with the local customer base (or the job adverts in the local newspapers) - or else you're kind of limited to the expat businesses in the area.

Maybe on a visit to your son you could stop by and chat up the local Mitsubishi and Suzuki dealers and see what they can tell you about the job market for mechanics.