We gave up on GS for roadside assistance in Mexico. There are Green Angels which will stop and help for free but you need to have extra parts available for them and you may need to wait a while for them. Get a Mexican cell (I got one for 300 pesos and it included 300 pesos worth of minuts) and dial "074" if you need assistance.
If you do opt to use GS, I would call them ahead of time and find out how that works - what number would you dial from your cell phone in Mexico, and what services do they use to tow you if necessary, etc. We found their help in both Mexico and the US to be pretty non-existent for us so we just stopped the coverage.
One last thing - if you go further south than Ensenada, particularly toward GN, then the roads will be more narrow. It's always a good idea to check your air pressure in your tires, check your brakes, etc. each morning before you head out.
We carry those orange cones so when we have had trouble (only twice) we can put those out to divert traffic away.
Never, never, never, never, never drive at night for a whole host of reasons.
Good luck and have fun!
Charlene
