The BMW 3-series has been around for 45 years, with seven generations chalking up more than a third of the brand's total sales.

It is the German carmaker's most popular model and you are likely to see more than a few when you are on the road.

But Mr Fong Kwok Shiung, 58, owns a rare one - a 1982 two-door, 2-litre six-cylinder manual 320. He bought the E21 - codename for the first-generation 3-series - from his brother, its first owner, in 1993 for under $70,000.

The strategic project consultant was driving a Ford Escort 1.6 Ghia then. "The Mk2 Escort was great fun to drive," he says. "But when my brother wanted to sell the BMW, there was no need to think at all."

Mr Fong has always liked the original 3-series, but never managed to get one mainly because there were not many here.

He believes his car is currently one of only three first-generation 3-series cars here.

The father of three grown-up sons remembers the first time he saw one. It was 1982, at a Shell station in Clemenceau Avenue.

"I bumped into an acquaintance who was driving his parents' red 316," he recalls. "That was the seed which planted my fascination for the E21."

The 320 is not the only car in the family. His marketing director wife Celine, 52, has a multipurpose vehicle, which is more practical for family needs.

Still, Mr Fong says the 320 "suited my lifestyle" and has been fairly reliable. In the 27 years of ownership, it has broken down only twice, both because the engine control unit failed.

"The manual five-speed gearbox has never needed any special attention," he says.

Nevertheless, maintaining the car in tip-top condition required some effort. In the early years, information about the car was available only in technical manuals, overseas test reports and authorised BMW agent Performance Motors.

Today, a few keystrokes will get you the details.

In 2011, the engine acted up, caused by a piston ring failure.

Mr Fong decided to rebuild the engine and found a reliable mechanic, who encouraged him to refurbish the entire car.

Work started in 2012. It involved stripping the car down and replacing everything which was worn. Rust spots on the body were removed and anti-corrosion coating on the undercarriage was removed and reapplied. The seats were reupholstered in nappa leather.

The project took more than two years to complete - in time for Mr Fong to grant his youngest son's wish to be picked up from school in the rejuvenated car on his 11th birthday in 2014.

But Mr Fong did not modify the car as he wanted it to remain true to its original form. Its 15-inch BBS wheels and Blaupunkt stereo set were left intact.

The car is in its original Opalgrun Metallic, with no unnecessary aftermarket adornments. Even the standard issue fold-down toolkit in the boot - a feature in BMWs of that period - is complete and pristine.

The certificate of entitlement has been renewed numerous times, most recently in March last year.

"It continues to be a joy to drive," Mr Fong says.