Visit www.costcotravel.com. Select the Rental Cars option from the available options on top. This will give you an overview of the four rental car companies that Costco is partnered with - Alamo, Avis, Budget and Enterprise. You will also be able to see their current offers. Any of these may be booked online.
Click on any of the four car companies to see all of their current promotions and discounts. Select the offer to see the details of the promotion, dates available and the terms and conditions. Some of these offers are only available on particular dates and on weekends/weekdays, so observe these guidelines. Use the navigation buttons on top of your web page to select the other car companies and see all of their special discounts. Some promos will allow you free GPS, free child seats or free a second driver. Choose the one that best meets your requirements.
To book any of the discounted rental car prices advertised on the Travel Costco website, select the red 'Click to Book' button on the top right of your web page. This will take you to the respective car company's website, and will automatically fill in the discount code number towards your applicable purchase. Here, you will also be able to view the final price for your purchase.