[4] He was conscripted to the Royal Air Force (RAF) towards the end of the Second World War aged seventeen,[5] and worked as a Motor Mechanics Instructor.
He secured his first retail franchise for Morris Motors in 1959, then during the early 1960s established showrooms in Bothwell Street and also in Paisley and Bearsden.
[8] He launched a finance company in 1963, meaning people no longer needed to involve their bank manager when purchasing vehicles from him.
[11] By September 2002, Arnold Clark had 97 dealerships and with annual sales expected to reach £1 billion, it was considered Scotland's largest private company.
[15] He remained as chairman and chief executive, thus being the company's highest paid director and was receiving almost £2 million a year by 2012.
[18] The Sunday Times Rich List 2016 estimated that the fortune amassed by Clark and his family to be more than £1 billion, making him Britain's first billionaire car dealer.
[20] In the 2004 New Year Honours, Clark was created a Knight Bachelor, for services to the motor industry, and for his community work in Scotland.
That year, Clark led the annual Tobermory race, before Drum was involved in a collision with a Royal Navy submarine, around five miles off the Mull of Kintyre.