We had our first in June, and he has now been on 26 flights all without incident (and usually to the great delight of the first-class passengers and crew). We usually gate-check both the car seat and the stroller (though now that he can sit, we moved to a super-collapsible stroller that fits into a backpack-sized bag and thus can go under a seat or in the overhead without anyone knowing it's a stroller). Taking them through security is of course no problem. But at the gate you'll need to ask for pink tags, and sure, there was an anecdote where someone got to gate-check theirs without an infant, but technically the free stroller and car seat are for passengers with infants. And you'll have two problems if your AA agent decides to enforce that rule: first, your 5th bag will cost $200, and second, there's a 5-bag maximum on checked bags to and from Brazil. So you might be stuck holding the goods at the gate. Not a predicament I would want to be in. I would rather keep the baggage to the 4x32kg and ship the car seat and stroller.