I like to boondock too, I never tought of boondocking in Mexico.
We boondock in Mexico but mostly when there is no campground close enough for us to get to or the nearest campground has deteriorated to the point it is no longer inhabitable. Most of our boondocking is at Pemex stations (gas stations) that are large enough to fit into - often similar to US truck stops. We have even seen a Quebec caravan boondocking in a Pemex - 20 rigs. There are other places where it is possible to boondock but a lot of it is inside information. Botanical Gardens parking lot. Butterfly preserve. Walmart/Sam's club. Some of the same rules apply for us that we follow in the US - not everyone follows the same rules or has the same requirements. We do not go to isolated places where we are the only occupants. We make sure there are people around and that they know who we are and what we are doing. We park where there is plenty of light. We met some people in a truck camper from Chile who had been on the road for 8 months and had not yet paid to park - their secret was a lot of fire stations. But we also have the idea that we stay in RV parks when we can because we do not want them to go out of business - there are times we need an RV park - we want to be able to find one when needed - support local business. That's a very basic idea of boondocking in Mexico - lots of people do it.