This question already has an answer here:
I recently purchased a one way ticket from Frankfurt, Germany to Salvador, Brazil with low cost carrier Condor. I am a Belgian citizen and don't need a visa for Brazil (or any South American country for that matter). I will be travelling overland, first to Chile and then further north to Peru. I have been reading (including questions on this forum) extensively about this 'proof of onward travel' but pretty much all the information I can find is anecdotal. I need hard proof and no personal experience. For example: this topic is basically the same question and the first answer begins with 'My answer does not reflect official rules and laws, just my own experience.' Not very reassuring, you can imagine.
So now, this is my personal situation. I want to know whether a bus ticket from a city in Brazil, to let's say Uruguay will be 100% enough proof for Brazilian immigration officers, both in my departing city as well as the arrival airport in South America. If not, what other options do I have?
I also have tried to contact the Brazilian embassy, but a couple of mail addresses have seized to exist and other ones just don't reply. I just don't want to get stuck when I want to leave.