flying in mexico is no different than flying in the us. the main difference is that you are required to file flight plans for every flight. this flightplans are then approved by the airport authority before taking off. no night vfr allowed. yes sometimes tipping expedites things or gets you better services (getting thr airplane towed and parked, cleaned up, gassed up, help with paperwork, baggage handling etc). i am talking less than twenty dollars. There's some requirements (insurance mainly, registration, airworthiness, etc) that need to be met in order to fly within mexico and theres also a sticker that you need to get to be allowed to take the airplane out of the usa (CBP). theres a one time entry fee of about 600 pesos (50 dollars) that you can pay everytime you fly into mexico or apply so that it lasts for a whole year. I have flown into mexico a ton of times and its not a big deal. those international handlers are probably a big rip off. central and south america is another story i could not tell as i a have never flown there.