Donald M. Rosen, 81, builder of a successful group of Philadelphia automobile dealerships, died at his home in Haverford on Sunday of complications from endocarditis.

Mr. Rosen was a fixture in the Philadelphia business community for more than three decades since opening his first car dealership, Don Rosen Cadillac, in 1979.

In 2015, Mr. Rosen told the Daily News he was inspired when he noticed a large number of Cadillacs in an apartment building driveway on City Line had license-plate holders from Center City outlets — even though there was a Cadillac dealer across the street.

“I decided to give the dealership a phone call,” Rosen told the newspaper. “I said, ‘I’m looking for a 1975 blue Cadillac convertible.' The salesman said, ‘We don’t have any,' and hung up.”

He said he was brushed off when he visited the dealership, too, so he bought it.

Mr. Rosen was born in Philadelphia, on Nov. 1, 1938, the son of Reuben and Tallu Rosen..

Mr. Rosen, who earned a bachelor’s degree from Temple University, branched out from the Cadillac brand and created a group of automotive dealerships representing a variety of vehicle brands in the Philadelphia region. For a time, his name was widely known due to his radio commercials.

Mr. Rosen supported many charities and served on the board of the Abramson Center for Jewish Life.

He and his wife, Roni, also supported the American Technion Society, University of Pennsylvania Philly Fights Cancer, Crohn’s & Colitis Foundation of America, JAFCO Jewish Children’s Village, the Jewish Federation of Philadelphia, the National Kidney Foundation, Terri Lynne Lokoff Foundation, Lankenau Medical Foundation, Admirals Cove Foundation, Ronald McDonald House, the YMCA, the ALS Foundation, and the Har Zion Foundation.

In 1976, Mr. Rosen’s father and uncle established the Maurice and Ruben Rosen Solid State Institute Building at Technion — Israel Institute of Technology in Haifa, Israel. Donald Rosen continued their work, funding a renovation to the building, which houses physics research, including work in semiconductors and microelectronics.

Mr. Rosen “loved spending time with his family and would never miss an opportunity to make everyone around him laugh,” according to a statement from his family. He spent time in Ventnor, at his home in Jupiter, Fla., and traveling through Europe and Israel.

“He especially enjoyed seeing the family grow, spending time with new babies and attending graduations and weddings. If there was a celebration, Don was involved, and wanted everyone to have a great time together. He was well known for planning the most elaborate celebrations, always the life of the party, which included surprises to entertain his guests," the family said.

An avid Philadelphia sports fan, he supported every team, never missing an Eagles football game and watching Phillies games late into the night.

Rosen is survived by his wife of 23 years, Roni (Pomerantz) Rosen, five children and two stepchildren, twelve grandchildren, one great-grandson, and several nieces and nephews. His first wife, Debra Gaye Rosen, died of cancer in 1989 at the age of 50.

Graveside services for Mr. Rosen took place Monday at West Laurel Hill Cemetery in Bala Cynwyd. Due to the COVID-19 pandemic, there will be no other service.

The family requests that instead of flowers, donations in Mr. Rosen’s name be made to Abramson Senior Care, at 1425 Horsham Road, North Wales, PA 19454; or the American Technion Society by mail at 55 E. 59th St., 14th Floor, New York, NY 10022.