Argentina and Chile are both really accessible for a 2WD car - even though some roads are not paved, they are graded and kept in a 2WD condition, just not using tarmac as the material of choice. However March is a rather sad month to bird in Argentina.
Birds: world 2160, WP 561, gWP 598 (#1 Czech WP and gWP birder!*), bird photos
Mammals: 257, mammal photos
* and my wife is #3 in both