Audi car was used in two sequences; firstly, Om Kapoor (OK) driving with his assistant to the Mohabbat Man's shooting set and secondly OK driving with Mike (Mukesh Mehra the 70's director) to the same set to show Mike the set for their new project. Although both were very simple scenes both the sequences were shot in CROMA in Film City.

Why CROMA :

Why this sequence was not shot in a real environment? To which Arjun replied, "Firstly we didn't want to take the risk of getting scratches on the body of the Audi Car costing 75 lakhs, and secondly they had to keep in mind the busy schedule of the actors, Thus instead of a live shoot we went ahead with CROMA."
Later the CROMA sequence was composited with moving background sequence which was shot later. The reflections, lights and shadows were then added onto the car's body.