SIR Arnold Clark, the billionaire car dealer, had an unquenchable work ethic and determination that he managed to translate into his main passion of sailing.

His son, Adam, told Glasgow Cathedral yesterday that he recently found out that Sir Arnold once won every event at Cowes Week on his 78-foot Maxi yacht, Drum, which once belonged to the pop star Simon Le Bon.

Such a success had not been seen since 1973, he added, when it was achieved by none other than the then Prime Minister, Sir Edward Heath, on his yacht, Morning Cloud.

Adam and his brother John jointly delivered the eulogy at the Celebration of the life of Sir Arnold, who passed away, aged 89, surrounded by his family, on April 10.

Over 1,000 people attended the celebration, among them Sir Tom Hunter, Sir Tom Farmer, Lord Macfarlane of Bearsden and his wife, Lady Macfarlane, Lord Macdonald of Tradeston, and Sadie Docherty, Lord Provost of Glasgow. Large numbers of Sir Arnold’s members of staff were also present.

The celebration, broadcast live via the Cathedral Television Service, was conducted by Rev Dr Laurence Whitley, the Minister of the Cathedral, who in his opening words described Sir Arnold as “one of the major figures of the last generation of the business and commercial world”.

“It is fitting that we have this service here, in the Mother Kirk of Glasgow, for Glasgow is proud of her famous son”, he added, “and proud today to call him one of her own”.

In his eulogy John Clark spoke of his father’s life and illustrious career. Sir Arnold was born in the East End of Glasgow, in James Nesbit Street, less than a mile from the Cathedral.

He left home at the age of 14 and during the war he moved to Arran, “where he quickly adapted to island life.

“He got up at 5am every morning to begin work as a paperboy before going to school. This strong work ethic, at such a young age, became the backbone of his future success”.

After his National Service in the RAF, he worked as a publican but in his spare time he used his RAF-acquired skills to fix cars and sell them for a profit.

He famously bought a Morris Ten Four for £70 and restored it before selling it on at a profit. In 1954 he opened the first Arnold Clark showroom in Park Road, Glasgow. It was to be the beginning of a distinguished career.

Today, the Arnold Clark organisation has over 11,000 employees and a turnover of £3.6 billion, and sells over 270,000 cars every year.

“I think his best marketing ploy to date remains the iconic black-and-yellow rear-window sticker,” John Clark said. “It has become part of the Scottish cultural landscape.

“If you put all the cars the group sells in a year, end to end, it would stretch from Inverness to Paris.” And to laughter he added: “Sometimes, driving down the A9, it looks like somebody is trying to do exactly that.”

Sir Arnold was knighted by the Queen in 2004 in recognition of his services to the motor industry and his contribution to the Scottish community. Mr Clark spoke of his father’s philanthropy and his commitment to providing training opportunities.

Over the last 60 years, Sir Arnold, “a true son of Glasgow”, provided “invaluable, long-term support to organisations, charities and community groups which are close to his heart”, among them the Prince’s Trust, Yorkhill Children’s Hospital, Kelvingrove Art Gallery and the Riverside Transport Museum.

Adam said his father worked six days a week, rising at dawn and carrying on until the small hours.

On Sunday mornings he would attend church and spend time with his family. He would study the week’s sales figures when they were sent to him on Sunday evening, and would work on into the night.

He was “completely devoted” to his staff and customers, and knew all of his employees by name. If you worked for Arnold Clark”, his son added, “you were one of the family”.

A moving poem, He Is Gone, by David Harkins, was read by Sir Arnold’s daughter, Amy Giovanacci.

Its closing lines summed up the nature of the Celebration: “You can cry and close your mind, be empty and turn your back/ Or you can do what he would want; smile, open your eyes, love and go on”. .

The celebration over, there was a brief private commital at Killearn.