Ray, that's a subject of some debate. Very few people/institutions have kept them successfully long-term. They seem to be in very poor health when imported and very fragile to change in environments. Most eat heartily once purchased, only to inexplicably stop eating and autotomize their tails within a few days to a few weeks. They soon die, even with the best care including optimum setup and veterinary health care. Very few survive and it's not really clear why. Though I've never tried mexicana, the situtaion with the oft-imported B. dofleini is similar, and I have first-hand experience with them.
There are some people here on these forums that surely know more about them than me, but from what I've heard, they do "best" in a densely planted, humid terrarium around 78-85F. My advise: unless you've got plenty of money to spend on an animal that is 95-99% likely to simply die, stay away from them.