In the film industry car are expendable goods. Since they finish their job, they are thrown, crashed and not a bit respected. This is the case of Fast & Furious 4 as well. In October 2007, after Dennis McCarthy was hired as the picture car coordinator, he commenced building around 240 cars, needed for production purposes. Replicas were needed for all sorts of stunts during the shooting. What would you do if you woke up one day and all these cars were in your yard?!
Here you can see the Inside Line`s guide to the vehicles used in Fast & Furious. Moreover, check out this link!