Rhino, Rola, Thule and other rack manufacturers have a full range of bike carriers that fit directly to the tow ball or connect into 40mm and 50mm hitches. Most carry 2 or 3 bikes but can carry up to 5 bikes in a hanging position.
Most bike carriers fold down to alloy access to the rear of vans and station wagons. Be aware, that by law if your vehicle number plate and rear lights of the vehicle are obscured then a light bar and number plate holder must be positioned on the rear most bike during transport.