Showroom spotlight | Sci-Fleet Motors

And so has the scale of the family business. From humble beginnings, with two franchises at Kedron and Windsor on Brisbane's northside, the Sci-Fleet Motors group is now the largest-selling Toyota dealership in Australia, and No.15 in the world.

Over the years, it has also added Lexus luxury car dealerships and Hino trucks. All up, they sell more than 20,000 vehicles a year from 10 locations across southeast Queensland.

But just like the satisfaction of that whiff of new-car aroma when you first climb behind the wheel, there is one thing that has not changed over those 34 years, according to dealer-principal Andrew Scifleet: An ethos of honesty and reliability. "Those old-fashioned values of customer service which were in place when the first two dealerships were purchased are still in place."

The reason, he says, is simple. "Family involvement in all aspects of the business has been a key part of our success."

The Scifleets have established themselves as the leading family-owned car dealership group in the Sunshine State. The group is ranked 34 in Queensland's Top 150 Rich List this year, with an estimated wealth of $304 million. Scifleet owns the real estate occupied by the dealerships as well as other property investments.

While Mr Scifleet, 41, is usually the public face of the company, his older sisters - Jane, Allison, Kathryn, Sarah and her husband Craig - all hold important roles.

The third generation is also starting to make its mark. "I have a nephew who works as one of our company accountants, his sister works with our management team and their younger brother is involved in our used-car operations and is working his way through departments to gain a real understanding of the business.

"We have strong governance from a family business point of view and an understanding of how everyone should be involved in the business. It enables us to reinforce our family values across the generations." The family business has tried to foster that same sense of belonging among the 450-odd workforce. More than one in five employees has been with the company for more than a decade, many for 30 years.

"We've really allowed our staff to come in and run the business as if it were their own," Mr Scifleet says. "We're here to guide the ship and make sure we're heading in the right direction. However, we put a lot of trust and responsibility in our staff. "Our steady growth over the years has enabled us to fulfil another important philosophy - promoting from within the organisation."

"Steady growth" could be seen as an understatement for the largest-selling Toyota dealer in the country since 1999. It runs Toyota dealerships at Kedron, Albion and Taringa; Lexus showrooms at Indooroopilly, Fortitude Valley, Southport and Maroochydore; and Hino outlets at Coopers Plains, Kedron and Nerang; as well as huge parts, pre-delivery and vehicle storage facilities.

The car sales sector has been a standout performer over the past couple of years, helped by low interest rates. Overall, the industry grew just over 10 per cent in the 12 months to December 2012, while Sci-Fleet Motors rose by double that. They head five entries from the motor sales industry in this year's list, including three debutants.

Despite a dip in the dollar and the downturn in the mining sector, which had helped boost sales, Mr Scifleet is optimistic. "We are definitely set up to expand and grow." In addition to Sci-Fleet Motors itself, the family owns two-thirds of Auto Corner Pty Ltd, which runs Toyota, Mazda and Hyundai dealerships at Mackay.

And they have a half-share in the Tweed Heads-based South Coast Automotive group, which sells a range of makes. Mr Scifleet says despite the size of the business today, the family group has not forgotten its roots, or the customers' support over the years, and it is strongly motivated to give back to the community and charities.

Recent causes include the Ride to Conquer Motor Neurone Disease and Go Blue for Autism Day. The group's Lexus Owners gift program donates equipment to charity on behalf of customers. "Our parents have set a wonderful example for us. In particular our mother is the glue that holds the family together. She is completely selfless and does so much for so many," Mr Scifleet says.

"According to my father, she is a true matriarch in the finest tradition. In his words, she would have made a wonderful elephant!" Mr Scifleet has a connection to another animal. The company has been a supporter of Australia Zoo for nearly a decade. Mr Scifleet even joined one of the expeditions to Cape York to attach satellite transmitters to crocodiles - and the late Steve Irwin named a huge saltie "Sci-Fleet" after him.

Like many blokes, Mr Scifleet loves cars and he's had the chance to put plenty through their paces. "The Lexus LFA has been the best by far. I was very fortunate to attend the launch of this supercar at The Nurburgring in Germany. It was a big thrill to drive it on such a renowned racetrack."

He was so impressed by the $700,000 V10 machine - which has a top speed of 325km/h and can accelerate from a standing start to 100km/h in 3.7 seconds - that the family bought one to use as a promotional tool for the company.

It's one of only 10 in Australia and 500 worldwide. Last October, they turned it pink, using a special vinyl wrap to help Queensland Reds and Wallabies rugby twins Anthony and Saia Fainga'a raise awareness for the National Breast Cancer Foundation.