The BMW M3s We Never Got

Generation III: E46 M3 CSL
Light, loaded, and at the limit. Grab the handle, slam the CSL's door shut, and you're treated to the tinniest tink this side of a Trabant. Turn the key, and the straight six coughs to life and then promptly stalls. When you restart it, there's a discordant choir of five or ten or fourteen exhaust heat shields all buzzing at different frequencies while the computer desperately tries-and fails-to keep the engine at a steady speed. You drive around slowly, patiently waiting for the illuminated yellow segments on the tachometer to gradually extinguish, indicating that the engine is warmed up and ready to be flogged. The racing bucket seat is comfortable despite being rock hard, but the ride is brutal and you hear everything going on around you. There's precious little sound deadening in the CSL, and carbon fiber-the roof, the inner door panels, and the center console are all made of the lightweight stuff-conducts noise like the walls of a cheap motel. The ducktail rear trunk lid, the rear diffuser, and the front apron are also carbon fiber, and the trunk floor is cardboard. But the CSL wears big brakes from the E39-chassis M5. It's pretty clear where selective weight loss was important-and with more than 240 pounds gone, the diet was a success. You're thinking that the semislick Michelin tires are warm because they're picking up pebbles and flinging them at the underside of the car. You tip in. Only slightly modified from the base E46 M3, the S54 engine boasts the same broad torque curve and chain-saw sound track. To your right, you spy a button labeled "Sport" and press it. Hmm, no discernible change-until you exercise your right ankle again. Suddenly the large, carbon-fiber air box under the hood sounds as if it's being ripped to pieces by the guttural, staccato intake pulses. In fact, the whole car seems like it's being shaken apart by the sound. Now freed from restriction by way of a five-inch air-box flap that swung open when you hit the button, this is the loudest intake roar you'll ever hear from a street car-it completely drowns out the buzzy exhaust note and transforms this M3 into a race car.