If your car has two rear doors, a hitch bike rack may prevent you from opening them halfway to store or remove your things. On the other hand, if you use a roof bike rack, you can open the rear doors without problems. The disadvantage of this type of bicycle rack is that they can complicate the entry of the car in some parking lots or garages, due to the height. For their part, hitch bike racks complicate driving a bit when backing up in the car, since the vehicle has been lengthened. However, with time you will get used to it, so any type of bike rack could be useful.