We have an agreement, it's called MERCOSUR (MERcado COmun del SUR, southern common market in English), but in practice only benefits the big corporations in the big countries in this region, Brazil and Argentina, the small business and common people are very limited to buy goods outside the borders by extremely high taxes (60% of the item in my case) and stupid quantity restrictions.
But let's stop talking about economics and politics, we will have better luck focusing on burn some two stroke oil ;)