You can't do this the way you want without using undocumented features.

If we have a look at Collection#add, we'll see this:

add: function(models, options) {

  //...

  for (i = 0, l = add.length; i < l; i++) {

    (model = add[i]).trigger('add', model, this, options);

  }

  //...

}

Note the fourth argument to trigger. And if we look at the documented interface for trigger:

trigger object.trigger(event, [*args])

Trigger callbacks for the given event, or space-delimited list of events. Subsequent arguments to trigger will be passed along to the event callbacks.

So the add will call the listeners as f(model, collection, options) where options is the same options what you passed to Collection#add. The result is that if you do this:

this.collection.add(predefinedModel, { undocumented: 'arguments' })

then you could do this in your callback:

triggerthis: function(model, collection, options) {

    console.log(options.undocumented);

}

Demo: http://jsfiddle.net/ambiguous/bqWwQ/

You could of course tunnel a whole array or object through options this way.

The third argument for add events isn't documented (at least not that I can find), the closest thing to documentation for this is a note in the 0.3.3 Changelog entry:

The ubiquitous options argument is now passed as the final argument to all change events.

I wouldn't recommend this approach but it is there if you need it; you will of course need to cover this in your test suite and you'll need to make sure you don't use any keys in options that Backbone will be using.

A safer approach would be to attach some extra properties to the model:

model.baggage = { some: 'extra stuff };

and then peel that off in the callback:

triggerthis: function(model, collection) {

    var baggage = model.baggage;

    delete model.baggage;

    //...

}

Demo: http://jsfiddle.net/ambiguous/M3UaH/

You could also use different callbacks for different purposes or pass your extra parameters as full blown model attributes.

There's also _.bind:

this.collection.on(add, _.bind(function(collection, model, extra) { ... }, context, collection, model, 'whatever you want'));

but that will bind arguments from left to right so you'll have to specify all the arguments that your callback will need.

Demo: http://jsfiddle.net/ambiguous/jUpJz/