The longtime advertising executive retired abruptly last month as chairman of Bates Worldwide, saying he planned to resurface in a more entrepreneurial venture.
With United Auto, he will be a hands-on operator but is expected to relinquish the Mercedes-Benz he drives. That make of auto is not among the 41 franchises the company represents in New Jersey, New York and Connecticut.
At Bates, Mr. Spielvogel worked with Hyundai Motor America, one of the agency's largest clients.
Mr. Spielvogel succeeds Marshall Cogan, who remains chairman of the executive committee of United Auto.
Mr. Spielvogel, also an investor in the auto dealership organization, will be responsible for the company's day-to-day operations, strategic direction and making policy.
He also said he plans to review the group's current advertising, now in the hands of Zimmerman & Partners, Fort Lauderdale, Fla.
As part of the management shift, Ezra P. Mager, already a director, assumes the new and additional role of executive vice chairman.