A firm handshake, one could argue, is just as important in an American auto sale as signing the contract or making the down payment.

The grandson of one of this country’s most successful auto dealers wishes he had the chance to give his “Pop’s” hand one last squeeze.

“His hand was like a giant bear paw,” Dave Sinclair III recalled. “He would say: ‘Give me your best shot’ and let us squeeze his hand as hard as we could.”

On Saturday, only a day after Dave Sinclair Sr. died of gallbladder cancer at age 81, the oldest of his 37 grandchildren was bustling about, like any normal business day, at the late Sinclair’s busy south county Ford dealership.

“There’s always going to be a Sinclair in the store,” he quipped.

That visibility and accountability played a large part in making the Sinclair family name synonymous with quality American car sales — and turning its patriarch into a highly respected local icon.

St. Louis-born Dave Sinclair Sr. got into the auto business in 1956. His resume already was diverse: World War II Army veteran, laborer, police officer.

“He was part of history,” said Dave Sinclair III, 28. “To hear him tell stories from memory was better than reading about it.”

While serving with the St. Louis Police Department, Sinclair’s perpetrators often were, ironically, car salesmen. The experience, his grandson said, taught him a valuable lesson about selling cars, and he made sure his children and grandchildren took it to heart, too: “Never lie, cheat or steal.”

“If you tell the truth, you never have to worry about remembering what you said,” Dave Sinclair III said. “He never wanted to be like the guys he locked up.”

Sinclair’s famous Ford dealership opened on South Kingshighway in 1966 and quickly became the leader in area car sales.

Then, 10 years later, Ford Motor Co. told Sinclair it wanted the business to move to South Lindbergh Boulevard in then-fledgling south county.

“He thought it would be the death of him,” his grandson said of the relocation. “It was the mid-’70s and nothing was out here.”

It turned out, though, to be one of the best decisions he ever made.

After riding out the economic recession of the early 1980s, Sinclair’s store became the No. 1 Ford dealership in the United States for three consecutive years.

He eventually opened two other dealerships on south Lindbergh, selling Lincoln, Mercury, Buick, Pontiac and GMC models. And despite that rocky start to their relationship, Sinclair eventually would refer to south county as the “epicenter of everything.”

An Oakville resident, Sinclair would be the first to introduce himself to new business owners in south county, but never projected himself as a hometown celebrity, his grandson said.

“If someone gave us business, he gave them business,” Dave Sinclair III said. “If he wanted to go out for a drink or bite to eat, he’d call one of his kids or grandkids and ask: ‘Do you know what bar or restaurant has bought a car from us recently?’ He was always willing to return a favor.”

Despite his humility, Sinclair became something of a household name in the St. Louis area. Perhaps it had something to do with his no-nonsense, “let’s talk,” television commercials, in which he would lay out his best deals from behind a podium and sign off like a true businessman: “If it’s not right, we’ll make it right. Thank you and here’s my address.”

“He never got those car dealer commercials with the screaming and flashing pictures,” Sinclair’s grandson said. “He always figured that if you couldn’t be clear about who you were, what you were selling or where you were located, how could you expect to sell any cars?”

Asked about the future of the ads that helped make his grandfather’s dealerships so successful, Dave Sinclair III said, “The podium will never die.”

Sinclair put his children and grandchildren to work for him as his business grew.

Dave Sinclair III says he first reported to work when he was only eight or 10 years old. He washed cars and served hot dogs and popcorn to customers before graduating to the sales floor at age 19.

It will be Sinclair’s extended family that keeps his dealerships going.

The three south county stores, along with a St. Peters dealership, were closed Monday as their founder was laid to rest at Resurrection Cemetery in Affton. But they reopened Tuesday with Sinclair’s four sons at the helm — or rather, behind the wheel.

“He has set such a precedent,” Dave Sinclair III said of his grandfather. “We want to keep matching it — and exceeding it.”

Sinclair is survived by his wife of 59 years, Patricia M. Sinclair of Oakville; four sons, Daniel Sinclair of Affton, David Sinclair of Kirkwood, John Sinclair of Oakville and James Sinclair of Town and Country; three daughters, Mary Detwiler, Kathleen Godfrey and Patricia Willett, all of Oakville; two brothers, John Sinclair of Rolla and Walter Sinclair of Las Vegas; 37 grandchildren; and one great-granddaughter.

Dave Sinclair III told the Call his family is thankful for the “outpouring of thoughts and prayers” it has received from the St. Louis community. Memorial contributions may be made to Backstoppers, Birthright Counseling or Catholic Charities.