James Thorpe, 42, was arrested later Tuesday and was being held Wednesday on a $3 million bond at a Dallas County jail. It was not immediately clear whether Thorpe had an attorney.
Thorpe denied pushing Phinney out of the vehicle in jailhouse interviews with Dallas-Fort Worth television stations. He said the car salesman jumped out while the vehicle was going about 50 mph.
Police in the Dallas suburb of Richardson were contacted after Phinney didn't return from the test drive.
"He never had any ill will towards anybody. He was the nicest guy in the world," Aaron Miller, the sales manager at Manuel Dodge, said in Tuesday's online edition of The Dallas Morning News.
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