The only American-made cars you'll see on the streets of Havana are the ones that were owned by private citizens prior to the 1959 revolution. If you owned a car before the revolution you could keep it, but Cuban citizens have not been allowed to buy automobiles in the decades since then. The government owns all newer vehicles, none of which were manufactured in the United States.
Families with pre-1959 cars take very good care of them, knowing they can't be replaced if they stop working. Privately owned automobiles are passed down through the generations like an inheritance, one of the few major posessions a Cuban can legally own. The tourism industry is the only area where the average Cuban can make much money, so many of these older cars are used as taxis (both legally and illegally).
Click here to see another old American-made car in Havana.