RCW 46.04.465: Rental car.

(1) "Rental car" means a passenger car, as defined in RCW 46.04.382, that is used solely by a rental car business for rental to others, without a driver provided by the rental car business, for periods of not more than thirty consecutive days.

(2) "Rental car" does not include:

(a) Vehicles rented or loaned to customers by automotive repair businesses while the customer's vehicle is under repair;

(b) Vehicles licensed and operated as taxicabs.