Hilary Duff has been banned from buying her dream car — a Porsche Cayenne Turbo — because she is such a bad driver.

The Lizzie McGuire actress had special driving lessons on MTV show Punk'd, but she was still given the warning by her business manager.

She admitted: "The car I want is a Porsche Cayenne Turbo. But my business manager doesn't want me to buy it — he says that I'm a terrible driver and don't need that kind of car."

"The other day I had a little accident because I was driving while I was on the phone."