Assume that buses and taxis will not have any kind of car seat. Car companies will rent them but whether they are what you're looking for is another issue. You would have to check with the car rental company whether they can accommodate LATCH-type seat. I imagine that would depend on how new the car is, wouldn't it? I'd be tempted to take the car option with a two year old unless you really don't think you're going any where far in Manuel Antonio. I have found the car seat great for flying with a small child but that's for long flights so they can sleep.

Costa Ricans generally adore small children so expect to be fussed over!