Like an RS badge to a Porsche enthusiast, CSL – for Coupe, Sport, Lightweight – is an adornment to deify for any BMW fan. But where these days a RS Porsche is an expected 911 variant, the CSL moniker has only ever graced two coupes from Bavaria. Released in 2000, BMW’s third generation M3 was the last of the series powered by the classic in-line naturally aspirated six, the 3.2-litre unit offering the highest specific output of any naturally-aspirated car on the market at that time. With individual throttle-bodies, VANOS variable valve-timing, forged steel conrods and crankshaft plus graphite-coated cast aluminium pistons, the S54 motor gave almost instant response and revved all the way to the 8200rpm cut-out, developing a peak 252kW at 7900rpm.