About National in Maryland Explore Maryland with your very own set of rental wheels. Whether you’re traveling for a weekend business trip or need something more long term for a romantic getaway or quality time with the kids, book your National Maryland car rentals today. Here on CarRentals.com, we’re proud to partner with National. A leader in the rental car industry, the company supplies us with their premier fleet of vehicles. So you can get behind the wheel of a cute compact for solo sojourns or rent something more spacious if you’re traveling with loved ones.