selling a vehicle

Selling Dodge Caravan in Costa rica

We will  be arriving  Costa Rica in December and need to sell our car before the start of January 2014.

It is a Dodge Caravan,2001 with canadian number plates. It has done approximately 302,000km to date. 

3 brand new tyres and front break pads (only 1mth old) new back breaks done 3 months ago.

It has cruise control, power steering. Air conditioning does not work (could be something simple ,  we never looked into it)

Getting rid of a motorcycle in Panama

I've got a pickle that I am hoping someone can help me with. I've driven a 1981 Kawasaki 440ltd as far as Guatemala and am planning to make Panama. At this point since I cannot afford to ship it over, I will need to somehow dispose of it. The bike didn't cost much so I would be willing to even give it away only I am unsure of how to go about doing this with the import visa and all. Is there a way I can give it away or "sell" the bike and still cancel my import visa? Any advice any one could give me would be a huge help.