They will more than likely have perks for loyal customers especially if you rent often. Booking a car online is one of the best ways to get car rental deals. Online vehicles that are booked in advance can provide a sizeable discount compared to a walk in client. Booking in advance either online or at the store will save you money as the company has secured you for future business. Deals available are sometimes geared toward a certain audience for example business, family or vacation rentals.