You'll find that when you pick up your car most major car hire companies will have a reception desk at the airport and this can be very convenient and hassle free, especially if you're not planning on staying within Duesseldorf itself. However, most car hire vendors will also have pick up/ drop off locations within Duesseldorf, so if you are staying in the city then you may want to consider this as an option. It's also worth noting the location of the hire car company
as some may not be based close to public transportation links, although, the majority of car rental firms will offer a pick up service but you'll need to book this in advance. If you plan to hire a car and drive around Duesseldorf to take in the sights, it's worthwhile taking a bit of time out and stopping off and visiting the historical Kaiserpfalz Kaiserswerth. The big advantage of hiring a car in Duesseldorf will not only allow you to enjoy the scenery within the city boundaries but will also makes it much easier to explore beyond the city.