OSM Wolrd: South America is a comprehensive vector scenery package. It updates coastlines, lakes, rivers, streams, roads, railroads, power lines, and adds polygon urban areas. All at a resolution of a point every 10 meters! (In FS-2004, a pixel on the ground is a square of 5x5 meters, so this scenery is as high as you can get without causing any trouble)
The scenery covers the South American area.
Due to the massive nature of the package it is only available in the AVSim Library (login needed but free).
OSM South America