Rails - Jul 2005 - Joins

This problem has stumped me for a long time.  I figured it was time to
seek expert advice!

Say you have the following models:

class Part < ActiveRecord::Base
    has_and_belongs_to_many :model_applications
end

class ModelApplication < ActiveRecord::Base
    belongs_to :model
    has_and_belongs_to_many :parts
end

class Model < ActiveRecord::Base
    belongs_to :make
end

class Make < ActiveRecord::Base
    has_many :models
end

The problem I''m having is I''d like to LEFT JOIN :model, and
:make in
addition to :model_applications.  For example:

@parts = Part.find(:all, :include => [ :model_applications, :model, :make ])

It seems like :include only works on directly related tables (eg.
:model_applications is directly related to :parts).