Another way to construct the prototype chain is by using Object.create, this way you don’t need to worry with constructor parameters. LandVehicle, for instance, receives numberOfTires as a parameter but we don’t care about that when creating the Car prototype chain, an alternative is to:

Car.prototype = Object.create(LandVehicle.prototype, {
horn: {
value: function() {
console.log(“Honk!”);
}
},
drive: {
value: function() {
console.log(“Vroom!”);
}
},
constructor: {
value: Car
}
});

http://jsfiddle.net/YVdxp/

From what I can discern: permission were changed. (?)

thanks for the fix!