This fast-casual cal-mex chain offers a "break" down allergen chart to help you build your own dairy-free (or gluten-free, or egg-free, or nut-free) menu item. Very helpful. Be warned though that most of their "proteins" (aka meats) contain dairy. Yep, this happens a lot, it is probably in the marinade or something to that Affect.
See their website to find a location, check out the menu and allergen chart, and even, in some states, order online: www.qdoba.com