There are lot of dealers that have a rental car agency on the premises. Either Enterprise or Avis. This is an easy way to give a service customer a loaner without tying up the dealers inventory. A lot of the dealers I have taken my cars to will give a slip which you take over to the rental agency and soon you are on your way. If the dealer supplies the agency with their products it is also a great way for the customer to try out a new model and maybe trade that car in service for a new one.