The iPhone 3G might be the hottest thing in the mobile phone industry, but it is setting things on fire once it reaches its end user.
An unsuspecting dutch iPhone 3G owner made a big mistake by leaving his new iPhone inside his car. He laid it on the passenger seat and when he returned, he found his windshield tinted. His nightmare was confirmed as he opened the door to find his iPhone 3G charred, and taking a portion of the seat along with it into the atmosphere.
The phone was not connected to the charger. It was left alone in the seat. The amount of time he had left the phone inside the car is not known. Regardless of that, you don't expect to come back to your car to see your phone in ashes.
Whether sunlight was instrumental in triggering the fire is not known. But as a safety and also security measure, remember to leave your iPhone away from direct sun light.
Source - iPhone news blog