You can find countless savings on your next car rental with Sixt's current deals section; like their airport weekend deals, early bird weekly special, and xxl weekend deals. Find Cheap Car Rentals. Sometimes starting at $17 a day or save up to 10% on your Sixt Car Rental. Plus you can save up to 35% when renting weekly, rent luxury sudans, mercedez, mini coopers, jeeps and more. Check their Current Deals for the most up-to-date list.