Katt Williams -- I Was Set Up In Rolls-Royce Rear Ender

Katt Williams and cars on PCH are bad news this week -- the comedian crashed his Rolls-Royce into a car-full of people he says taunted him and cut him off in traffic ... and Katt claims they caused the accident on purpose.

Katt tells us ... he was driving on PCH Monday night when a beat up Honda pulled up alongside him and started taking cell phone pics, and as he put it, "talking s*** and trying to start a fight."

According to Katt ... the Honda swerved in front of him ... forcing him to slam on the brakes. Katt says he couldn't stop in time and the Rolls rear ended the lesser car. He's convinced the Honda people were looking for a payday.

Cops tell us the Honda driver was taken to the hospital with minor back injuries.

The Honda driver accused Katt of speeding ... but cops didn't buy it. They tell us they believe Katt -- who found more trouble on PCH 24 hours later.