Over the years, BMW has produced some really handsome and striking coupés, with the E9 Series setting a standard that has evolved substantially since the Karmann-built model was introduced in 1965 as the ‘New Class’ 2000 C and CS. It used the 2000 saloon’s running gear but in 1968 the body was then altered to accommodate BMW’s famed inline-six, initially with 2.8-litre capacity. In 1971, this, in turn, was replaced by the 3.0 CS and CSi. Then, in 1972, the 3.0 CSL was produced as a homologation special to make the car eligible for the European Touring Car Championship, Deutsche Rennsport Meisterschaft and USA’s IMSA racing series, a highly successful move that led to the creation of the immortal ‘Batmobile’. A 3.5-litre version later appeared to contest the Group 5 championship while a 2.5-litre road car was offered in response to the 1973 world oil crisis. Quite a pedigree, and one that BMW was keen to build upon…

It appears as though a ‘taller’ version of the 3.0 CS was proposed but this was turned down by the company’s Executive Vice President of Global Sales and Marketing in Munich, Bob Lutz. The Swiss American automobile executive is more regularly recognised for his exploits with GM, Ford and Chrysler, but he was a member of BMW’s board of management from 1971 to 1974, and it was during this period that he instigated development of what was to become the E24 6 Series, which was based on the E12 5 Series saloon. The new model was designed by Paul Bracq, the company’s design director from 1970 to 1974, and boasts sleek, elegant lines with narrow pillars and deep windows. The car was launched in 1976 as a 630 CS (2986cc carburettor) and 633 CSi (3210cc fuel injection), again with bodies built by Karmann.

But in 1978 production was moved inhouse to Dingolfing, a move coincident with the introduction of the 635 CSi. As the badging indicates, under the bonnet is a fuel-injected 3428cc tuned to develop – depending on the market – around 160kW at 5800rpm and 310Nm of torque at 4200. There was a choice of a wide- or close-ratio five-speed manual gearbox or a three-speed ZF automatic (later to become a four-speed). A subtle but significant change under the skin took place in mid-1982 when the 6 Series was retooled to sit on the new, improved E28 5 Series platform.

The 6 Series is an easy car to get in and out of but despite its overall length of 4 758mm, the interior is not particularly roomy, especially in the back if someone long-legged is sitting up front. The car is more of a luxury 2+2 than a four-seater grand tourer. Although an option, an electric sunroof was specified for most cars, which cuts into headroom a little but, overall, thanks in particular to the generous glasshouse that creates such a light and airy environment, the cabin is a pleasant place to be.

It is comfortable, too. You immediately settle into the form-hugging Recaro front seats, which offer plenty of adjustment and although the steering wheel only adjusts for reach, a satisfactory driving position is quick and easy to achieve. The full-width facia has an angular instrument binnacle and a deep, wide hangdown console angled towards the driver – an ergonomic ‘must-have’ feature of the 1980s.

Automotive electronics were also making their presence felt with comfort and convenience features including an onboard computer, strip-light service indicator, fluid level monitoring, climate control air conditioning, cruise control and an LED clock, items today taken as a given in mass-production vehicles but 30+ years ago were seen to be innovative. Power windows and mirrors – with demist – were also standard. The dual round headlamps on post-1987 models featured two-stage reflectors that provide better low-beam spread.

But it is the engine that is this car’s crowning glory. BMW’s in-line six is without doubt one of the automotive world’s greatest powerplants, to this day surviving all manner of economy and emissions legislation to provide super-smooth performance. The single overhead-cam 12-valve unit is so s-m-o-o-t-h – the crank boasts 12 balance weights – and in this pre-catalytic converter guise has that distinctive thrum that can be recognised from the twin exhausts from far away. This car’s manual box is similarly a joy to savour, superbly precise in its movement around the gate. The motor spins easily to the rev-counter’s red line that starts at 6000 and there is little to be gained by pushing further, there being ample torque to maintain forward thrust once changing up a gear. With the B10 engine, the car’s top speed increased from 227 to 250km/h and the 0-100km/h time lowered from 6.8 to 6.4 seconds.

Enhancing the fluidity of progress, the all-independent suspension – MacPherson struts and lower control arm up front, coil-over struts with semi-trailing arms at the rear, both ends with a stabiliser bar – provides a stable and absorbent ride with minimal body roll through the corners. Dual-jointed half-shafts complete the package. Standard footwear was 220/55VR14s but this car features Alpina 7J alloys shod with 205/55R16 rubberware, which fill the wheelarches more convincingly. The power-assisted steering is a ZF ball-and-nut system, which proved to be surprisingly heavy at slow speeds but on the move it was easy to appreciate the absence of any fidget while still getting feedback from the Alpina four-spoke wheel. ABS brakes have ventilated discs up front and solid rotors at the rear.

In 1983 an M635 CSi was introduced that came with an engine upgrade, the M88 engine as used in the M1 supercar, which pumped out 210kW at 6500rpm and 333Nm of torque at 4500. The car was fitted with a 25% limited-slip diff as standard. Available only with a five-speed manual gearbox, the M moniker says it all – it was the powerhouse of the range. Race versions of the car scored numerous championship titles in Europe, Germany, Belgium, Australia and New Zealand. It also scored victories in the RAC TT, Monza 4 Hour 500km, Spa 24 Hour and Nürburgring 24 Hour races, feats less well known than those of the previous Batmobile.

When launched in South Africa in 1983, the special-order purchase 635 CSi became BMW’s flagship model with a price of R65 000 for both manual and automatic – the same as the otherwise range-topping 745i. Consequently, it is a bit of a rarity and in my estimation something of a sleeper in the classic car stakes. While perhaps not quite the ‘ultimate driving machine’, it nevertheless is a very rewarding car to drive.

Production of the E24 6 Series ended in April 1989, and it was succeeded by the E31 8 Series that, like what happened with the E24 over the E9, somehow did not quite possess the charisma of the outgoing model. But today, the E24’s many attributes – amongst them style, performance and build quality – can be put into context and fully appreciated.