BMW’s M division has a strong reputation for creating cars that increase the pulse of driving enthusiasts, and the coveted CSL badge really gets those hearts racing as the cars that bear this icon tend to represent the ultimate blend of raw power and surgical precision. Yet for every CSL vehicle that does make it into production, there are others that are hidden away under sheets. Some of these one-offs may have pushed the limits of engineering too far and were simply too radical, costly, or niche to make it much further.
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