Ken:
Before I ER'd I was an attorney in several states. *I also represented a large multi-national company in Mexico on many matters. *I had to use Mexican lawyers even though it was my US client, I was fluent in Spanish, and knew the law. *Mexican law is an area that has layers of political and legal ambiguity, and requires that you obtain a duly admitted and licensed Mexican lawyer to advise you. *Its similar to getting an in-country guide who knows the trail from having walked it over the years as opposed to reading an off the rack guidebook.
I would suggest before you obtain the services of a Mexican lawyer you get several referrals from someone who is trustworthy and knows the type of transaction you are trying to do. *You WILL NOT FIND SUCH INFORMATION ON THE NET! *Do't do anything in Mexico without a complete due dilligence on the players and the transaction risk. * Even very Smart people get shorted in Mexican deals. *Be careful!