BMW Group Classic invited us to check out some of its rarest gems, including that Z3 roadster with a V12 engine. We were also allowed to get familiar with a limited-run production model that was only sold in South Africa. A little over 200 units of this E23 7 Series were made at Plant Rosslyn. However, this one’s even rarer since it’s one of just 14 cars equipped with a manual gearbox.

What made it truly special was the engine. The 745i SA aka M745i was powered by the M88/3, which was an evolution of the M88 found in the M1. That’s right – BMW put a supercar’s engine into its fullsize luxury sedan. This naturally aspirated 3.5-liter inline-six made 282 horsepower and 340 Newton-meters (251 pound-feet) of torque. It was actually slightly more powerful than the mid-engine supercar.

Separately, BMW sold the namesake 745i in other markets with a turbocharged inline-six in Europe. Initially, it was the 3.2-liter M102 unit from 1980 until 1982 before being replaced by the larger 3.4-liter but equally powerful 3.4-liter M106. The latter was offered until the first-generation 7 Series was retired in 1986. Both engines had 248 hp on tap, making them 34 hp less powerful than South Africa’s unofficial M7. However, forced induction gave the European model a torque advantage of 40 Nm (30 lb-ft), at 380 Nm (280 lb-ft).

As to why South Africa’s version was different, it had to do with packaging constraints. The Euro model had the turbocharger mounted on the right side of the engine bay. On a right-hand-drive car, the steering column would’ve collided with the turbo. BMW engineers from Plant Rosslyn came up with a solution by mounting a naturally aspirated engine. That M88/3 was also installed in the sexy M635 CSi and the original M5 (E28).

There was more to the 745i SA than its special engine since it also got the brakes from the M635 CSi. In addition, it had wider wheels than the European model, a slightly wider body, and even an M logo on the kidney grille. BMW never made a true M7 but you could say this one got close.