AS the stereotype of the dodgy car salesmen has been providing lazy comedians with gags for most of the post-war years, motor traders and religiosity rarely go together in the popular imagination.

However, 50 years after opening his first showroom in Glasgow, Sir Arnold Clark, of the eponymous motor trade giant, is combining life as one of Scotland's richest men with his role as a church elder.

Between services he may be locked in a battle for market share with Sir Peter Vardy, who heads the listed rival formed by his father Reg, but as well as a common love of an enriching trade, both share a commitment to faith.

In Vardy's case that means ploughing millions into supporting ''creationist'' education. Significantly, Clark won his peerage in the last New Year's honours list not only for his success on the forecourt, but for the work for the community which he conducts in a quieter way by supporting many charities.

The 76-year-old Clark, whose 125-strong chain nearly doubled profits to (pounds) 44m on sales of (pounds) 1.5bn last year, says the secret of his commercial success has been treating people right, in accordance with a company culture he has deliberately cultivated.

''I always kept my books in apple pie order,'' he says, wincing at the memory of the hefty bills his honesty entailed in a bygone age of 60% tax rates.

Central to growing sales has been a policy of playing fair by punters, the sense of which as a customer-retention strategy he learned selling vegetables door-to-door as a schoolboy in Townhead, Glasgow.

''I wanted to do it right and to ensure that my customers felt I treated them right. If someone came with a complaint I never said no. I always spoke to them and tried to help.''

Before he opened his first repair facility that could mean giving them a cheque and sending them off to a rival, recognising that satisfied dads would spread the word to their mates and children.

With the business - spanning car sales and repairs as well as finance and insurance - growing rapidly he insist that remains the case today and those who believe giants like Clark simply pile it high and sell it cheap miss the point.

''You don't buy popularity, you win it. You don't put flowers in the car, you give people a little bit extra like a radio in it,'' he says, maintaining that the business always prices ''properly'', not just low.

His characteristic warmth cools noticeably in response to suggestions that the firm's muscle has made growing almost a formality by giving it an unfair advantage over smaller rivals, 28 or more of which the company has gobbled up in its time.

''I had a tendency to expand the business in terrible times [and] all the businesses I bought were from families who sold to me willingly. I have never asked anybody would they sell their business to me. I didn't screw them to the ground or people would not want to sell them to me.''

Turning those unprofitable outfits into winners has been a simple business, of ensuring they offer enough models with the right marketing and management support, he says. Senior employees, however, say the company's chairman and chief executive has an unmatched understanding of the trade and its finer points.

Industry-changing innovations about which he makes little noise include having the first showroom to open at weekends and providing the impetus for the UK's first weekend motoring section in a newspaper with adverts in the former Evening Citizen.

Possibly the shrewdest move with the biggest ramifications, however, was the decision to open his first outlet trading only in used cars, after years selling motors which he fixed up individually.

No-one had ever bothered to treat those on a second-hand budget with such respect. It was another three years before he was entrusted with his first new car franchise by the venerable Morris but by the age of 42 he could have retired if he had wished.

The ability to work hard was evidenced from his schooldays when, as well as hawking vegetables grown by his steelworker father, he did milk and paper rounds. He combined his first job as a shoe designer with the Co-operative in Shieldhall with two others.

A readiness to go his own way was demonstrated just as strikingly during his service as a conscript motor fitting instructor in the Royal Air Force. ''I was sitting there swatting up while all the boys were out drinking beer,'' he recalls.

Having achieved his ambition and then some, his wealth now allows him to enjoy a luxury undreamed of on the stair of the ''wally close'' tenement of his youth.

''I will buy whatever I want to buy, and I will buy the best,'' he says, speaking admiringly of the marble floors in his home in Spain and a comfortable holiday billet in the north of Scotland. He was able to indulge a passion for yacht racing for years without worrying about the cost.

Nonetheless, ostentatious consumption is something he does not go in for, he says - noting the 1970s vintage boardroom in the company's Pollokshields headquarters has not been changed since the building was acquired for ''sweet nothing'' from Tarmac years ago.

What he does reserve especial enthusiasm for is the fact that the company's success has allowed him to provide a good life for his family, including 10 children. All six sons and four daughters usually come for Sunday dinner with Clark and Lady Philomena, his second wife, at the family house in Killearn.

Although none are directors of the company, many work in senior management roles.

Flotation has not featured on Clark's agenda and the children's interests are protected by the fact that the company is owned by himself and a family trust, ensuring continuity when his work is ended.

However, with plenty to do providing input to an executive team whose abilities he rates highly, as well as introducing himself to all new staff on their first day, Clark is in no hurry to drive into the sunset.

IN THE FORECOURT OF SIR ARNOLD

1927: born in Townhead, Glasgow. Left school with no qualifications aged 14. Conscripted into Royal Air Force aged 17 and served four years, culminating in work training motor fitters.

1948: started selling cars which he did up himself, using (pounds) 160 savings to get started.

1954: opened first showroom in Park Road, Glasgow.

2003: awarded knighthood.

Best business moment: Acquisition of two big family-owned Aberdeen dealerships for (pounds) 9m in the 1990s.

Worst business moment: Worrying if I had bitten off more than I could chew in making those purchases.

What drives you?: ''I like to be successful. I'm very competitive.''

What car do you drive?: I always buy from the family company's

stock. Currently I drive an Alfa Romeo GT.