Hello NJCaramelo,I am sorry for what happened to you. Next time, do not offer the cop money. If he threatens you with writing you a ticket, let him do it. Ask for his name, rank and badge number. After he has done so (he is forced to by law), tell him that you will contest these charges in court and will request his appearance before the judge. For the cop, that means he can kiss his "franco" (free day) goodbye. Cops must appear in court on their own time. If he writes the ticket, let him do it. Be nice, but remain firm. In court, explain your case to the judge, bearing in mind that judges know Argentine cops better than anyone, and know exactly what they're up to. I am sure he will disregard the charges immediately.
If the cop threatens you with taking your car, just remember that as long as you're in it, he can't touch it. That's kidnapping, or "privación ilegítima de la libertad" in Spanish. Ask your Argentine husband to tell you about the funny case of the person in Pilar who owned a brand new BMW and had failed to pay the "patentes", but when stopped by the police, remained in the car for hours, and the cops had to let him go (he was a lawyer).
Just remember that the cop is in this argument with you only because he wants money, and the minute he realises that bribery is not an option, he will let you go. And don't be scared, cops here will stop you for no reason at all and tell you how deeply in trouble you are, when in actual fact you've done nothing, just for a few bucks. Pretty much like contractors, handy men and plumbers do when they want to charge you more.Again, I am really sorry.I hope this helps,Cheer up!Ernie