Ah-ha. Maybe this partly explains why Lindsay Lohan was supposedly desperate to make it appear that she was a passenger, not the driver, when her Porsche collided with a truck on June 8. (And also why she allegedly really, really didn't want the truck driver to contact police.) Because of her past troubles behind the wheel, the insurance policy for "Liz and Dick," the movie she's currently shooting, forbids the actress from driving, TMZ reports. Lohan returned to work following the accident, and it appears that (so far) the insurance company hasn't taken any dramatic action. The movie's production company, on the other hand, has warned Lohan of the dire impact of another driving incident.