I know of a few food trucks that served good enough food, made enough money, and have enough of a following they opened up brick and mortar places. Sometimes the truck remains parked outside. Even seen one place that brings the truck to fairs and the like.
Having traveled a bunch in life, sometimes in small towns, especially those north of the 40th parallel, I head for the taco truck if I see one and I'm in the mood for Mexican. Usually better than the sit down place run by gringos who lived in Cali or AZ for a year or two and think they know how to cook Mexican food.
And tamales from an ice chest in the trunk, being sold my a viejito who's esposa made them last night are the bomb.
Geno