Yes. Additional drivers must be present and added to your rental agreement when you pick up the rental car. There may be a charge for each additional driver; Hotwire Hot Rates cover only one driver. The rate for additional drivers will be determined by the car rental agency.
Please note that any additional drivers must be at least 25 years of age with a valid driver's license and a credit card in their name. See also: Will I need a credit card as a deposit at the car rental counter?