Pure RUBY PORO to illustrate business logic separation from Frameworks.

car_rental.rb

class Company
  include Address, Owner, Email, PhoneNumber
  attr_accessor :name, :address, :phone_number, :email, :owner

  def initialize(name)
    @name = name
    @address ||= address #new company address
    ...
  end
end

class Vehicle
  attr_accessor :reg_plate, :make, :model, :date_of_reg, :seat_capacity, :lincese
end

class Address
  attr_accessor :line_one, :line_two, :city, :state, :post_code, :company, :owner
end

class Owner
  include Address, Company, Email, PhoneNumber
  attr_accessor :first_name, :last_name, :address, :email, :phone_number

  def initialize(first_name, last_name)
    @first_name, @last_name = first_name, last_name
  end
end