John Travolta's car is a TVR Tuscan which cannot be sold in the United States because it does not comply with federal emission level standards.
TVR were getting on average 50 emails a day from the USA from people requesting how to purchase a car after seeing it in the film.
Very little of the bus/helicopter scene was CGI. The director insisted that a real helicopter be used that could handle the load. This made the crew and the pilot extremely nervous as the load was almost 80% of the helicopter's capacity. The stunt crew held firm on the scene where the bus crashes into a meeting however. That was completely CGI as the pilot insisted that it was way too dangerous to attempt it even with a fake building.