DMZ 1.7.1 (DataMapper OverZealous Edition)

[eluser]YaZz[/eluser]
First off, just want to say, friggin' nice work!

Now working with this concept, I feel that my head just can't get around some parts, or simply put, I'm just incredibly dumb at the moment.

What I'm trying to achieve is grouping up tables nicely to make accessing easy.
I have a table for categories, products and product_images.
I've set up the models like this:

Code:

class categories extends DataMapper{
    public $has_many = array('products');
    function __construct($id = NULL)
    {
        parent::__construct($id);
    }
}

Code:

class products extends DataMapper{
    public $has_one = array('category');
    public $has_many = array('product_images');
    function __construct($id = NULL)
    {
        parent::__construct($id);
    }
}

Code:

class product_images extends DataMapper{
    public $has_one = array('products');    
    function __construct($id = NULL)
    {
        parent::__construct($id);
    }
}

My problem here is... how do I actually access the product_images. I can get to the products... But that's it. Am I thinking this the wrong way or is there another way to actually achieve my goals?