A couple weeks ago, Lindsay Lohan's rented Porsche hit the back of a semi and totaled the pricey sports car. She initially claimed she wasn't driving at the time -- a big fat lie -- but now we know why she was so anxious to say she was in the passenger seat.

Seems the insurance policy taken out by the production company behind 'Liz and Dick,' the Elizabeth Taylor biopic LiLo is currently shooting, had some pretty serious restrictions on her behavior. TMZ insiders say the insurer was so nervous about covering Lohan that it demanded she not even drive a car while the film is being shot.

She'd apparently been driving anyway, and no one seemed to care -- until that nasty wreck.

Thus far, the insurance company hasn't tried to take any action to cancel the policy, but it's now been made abundantly clear to Lindsay that she has to obey the policy directives. And that means no getting behind the wheel.

Meanwhile, the driver of that semi is claiming injuries and has now retained an attorney. So the whole saga may not be over yet.

More From ScreenCrush