Back to the classic stuff, and the seventh most expensive BMW on our list is a 1978 320i Turbo IMSA. Based on the E21 320i, this was a momentous project for BMW as it began to explore turbocharging in earnest. In fact, the 320i Turbo IMSA was created with the hidden agenda of developing a turbocharged engine for future use in Formula 1. Two cars were built by BMW Motorsport for the factory IMSA team, but after Porsche decimated the field through 1977, more work was needed. Thus, chassis no. 003 was born as a lightweight version, shedding some 300 pounds.
The car you see here is that very first and only lightweight 320i Turbo, and its fiberglass body got a one-piece hood with integrated fenders, a front splitter, and a wider rear end. Only two more examples of the 320i Turbo were ever made. Sadly, once BMW got what it wanted from engine development, it canceled the 320i Turbo program, which team and crew members felt was still brimming with potential. As a truly unique racecar, this sold for an eye-watering $731,000 at RM Sotheby’s 2018 Monterey auction.
With McLaren’s help, the M12/9 2.0-liter four-pot fitted here produced north of 600 hp, but future F1 engines based on it could more than double that. Easily.
