There's something to be said for keeping it real. Making a movie? Keep it real. Getting interrogated by the cops? DO NOT KEEP IT REAL.
While it's obvious that a film like Iron Man requires a planet's-worth of special effects, stuff like wrecking cars usually shouldn't. We all saw how poor choice of CGI affected Ithe fourth Indiana Jones movie.
That's why it's refreshing to see that some of the fancy cars destroyed in Iron Man 2 were real. Tony Stark's Rolls-Royce getting destroyed at a race in Monaco was legit (but filmed in California).
Rolls-Royce built two near-identical Phantoms for the filmmakers at $438,000 a pop. According to the New York Times' own Jerry Garrett, one has a cool box in the back and the other doesn't.
To get the cars all destructified, the body panels were stripped off and then rigged with charges. After they were put back on, everything was cleaned up using Bondo and a fine touch. Then it all got blown up.
The final resting place of the wrecked Rollers is a prop warehouse in Downey, California (no relation to the movie star).
On the other side of all this, autoofcars2011.blogspot of the old-school racers provided by the Historic Grand Prix Association were hurt.
Fun facts: "The blue and white Stark Industries race car was driven by the stunt driver Tanner Foust. The yellow Kodak car, the only other vehicle that was capable of running had the driver's name of "Elon Musk" painted on the side. Mr. Musk, the chief executive of Tesla Motors, had allowed the filmmakers to use his SpaceX facility in Hawthorne, Calif., as the site of the film's "Hammer Industries." He also made a cameo appearance in the film." - Jerry Garrett