The availability of optional extras depends on the car rental agent in Round Rock and even if they are booked online they are not guaranteed. The following extras can be booked on Autoprio.com: GPS – Satellite Navigational System, Luggage racks, Wi-Fi Access, Child toddler seat, Electronic toll pass, Additional driver, Snow Tyres, Roof Rack, Booster seat, Infant child seat, Ski Rack and Snow Chain Set. Please note that most of the optional extras are not included in the rental price and can be purchased at the time of booking or at the rental desk in Round Rock. The cost of the optional extras are displayed at time of booking in the Rental Conditions.