After hitchhiking a sailboat and crossing the Atlantic from Europe to the Caribbean, my travel mate and I went from the Dominican Republic to Honduras and that's where the 4 country land hitchhiking started.
Statistics on vehicles hitchhiked:
Cars
Trucks
Motorbikes
Taxis
Buses
Countries hitchhiked:
Honduras
Nicaragua
Costa Rica
Panama
I found it way easier to hitchhike in Latin America than in Europe. It took max 15 minutes to get picked up and drivers were always really friendly. Even if a car is full, because the rule are very flexible or there is no one to reinforce them, we could easily get in the open trunk and travel there which I found a lot more exciting.
I like to travel slow so it took 2,5 months to go through these 4 countries, and it was still faster than I should have.
People are just more open to strangers and not as afraid as in Europe. So I found it much more enjoyable and easier.