When Guido drives up to the Cinecitta film studios in his open top Lancia with his producer as passenger, parked outside (to left) is a (quite distinctive) two tone white and blue paint job rear-engined (flat front radiator) car (another Lancia?): as soon as they pull up inside the lot, as they exit the car and walk around the lot, camera pulls back to show an exact same (license plate same /similar) car parked on other side.
Early in the film, when Guido is drinking the coffee, you can clearly see that the cup is empty.