I don't have an answer for you, but can you explain how you overstayed your tourist visa and how this can be prevented? From what I've read here and elsewhere, it is as simple as taking a ferry to Uruguay and back after the 90 days, right?
As was stated in the thread you posted, you pay the fine on your way out of the country. I wouldn't count on them automatically giving you 90 more days on your way back in. If they want to, they can give you 30 days on a tourist visa. This happened to me when they saw that I was leaving the country every few months.
You may just want to stay put if your visa is already expired. You'll be charged the same fine no matter how long ago your visa expired.
yeah - im goin to uruguay to visit... so wanted to make sure i could clear this up or pay the fine on my way out from buquebus... to save me a trip to the embassy... as it turns out, yes there is an place i can pay a fine.. then move on to the line to travel. : o)thanks