The Black Eyed Peas star was furious when he discovered his expensive vehicle had been taken while he was attending his album launch party in Los Angeles.
He tweeted: "Where is my f***ing car ... ??? This isn't funny anymore. (sic)"
After calming down, he took to the social networking site again and wrote: "I'm going to be optimistic and pray that my car is returned and is safe."
Fans responded to his angry tweets with kind words such as: "u don't deserve this (sic)" and "You will find it".
Director and producer Ted Kennedy also showed concern and support, tweeting: "Did you find your car yet @iamwill? I found mine and it feels great! Amazing new music coming from you. (sic)"
He also said he believes the payback for this crime should be "hard and swift".
In May, will.i.am revealed he once he stashed $400,000 worth of uncashed cheques in the glove compartment of his car.
He added: "You don't know anything about financial literacy when you come from the ghetto."
And in June 2010 one of his cars had £7,000 worth of items stolen from it, some of which belonged to friend and fellow pop star Cheryl Cole.
