Which are the right :joins for two models in which one has two belongs_to the other same model?

Hi all, here is the main picture (obviously some snips are made):

class JobFile < ActiveRecord::Base   belongs_to :car   belongs_to :counterpart_insurance, :class_name => 'Insurance', :foreign_key => 'counterpart_insurance_id'   belongs_to :customer_insurance, :class_name => 'Insurance', :foreign_key => 'customer_insurance_id' end

class Insurance < ActiveRecord::Base   has_many :accident_counterparts, :class_name => 'JobFile', :foreign_key => 'customer_insurance_id"   has_many :accident_customers, :class_name => 'JobFile', :foreign_key => 'counterpart_insurance_id' end

class Customer < ActiveRecord::Base   has_many :cars, :dependent => :destroy end

class Car < ActiveRecord::Base   belongs_to :customer   has_many :job_files, :dependent => :destroy end

Now, I would like to have all the customers that have a job_file that deals with an insurance, I'm a bit stuck at writing down the joins clause for the named scope:

  named_scope :insurances_in, lambda { |array| {     :joins => [{:cars => {:job_files => :counterpart_insurance}}, {:cars => {:job_files => :counterpart_insurance}}],     :conditions => "insurances.name LIKE '%#{array.join("%")}%'",     :group => "customers.id" }   }

Is this right? Thanks for the help G.