I am the poster that Barnacle mentioned. We flew our plane, a Piper 180, to Belize from NE Texas. What happened with the fuel is true--it was almost all stolen, a little each day. Flying thru Mexico was a pain in the butt too, but if you have a twin engine so you dont have to stop as much it may be better for you.
It was an adventure, but I wouldnt do it again.