Rich One said:"....I had crossed the border three times with just my passport and an Argentine-registered car with no problems."
El Queso...??
If I understand you correctly if I own an argentine-registered car and are on a tourist visa, then I CAN drive out of the country.....???
why don't you just go to or call Buquebus and see what they say?
they told us at check in (foreign car/DNI) that we could not leave the country. I suppose they should be able to tell you before you get your ticket too...