Warren Buffett's 2006 Cadillac was sold to a New Yorker for $122,500 in an on-line auction that ended Thursday. That's $110,500 more than it would have been worth if the Oracle of Omaha himself hadn't owned it and signed the dashboard in black marker.
This time, Buffett is auctioning a beige 2006 Cadillac DTS. The DTS is a roomy, comfortable front-wheel drive car powered by a 275-horsepower V8 engine. Proceeds from the sale will go to Girls Incorporated of Omaha, a local chapter of the national …