BMW 5 Series E60 M5

The E60 is the BMW that decided a four-door sedan should sound like a Formula 1 car. From 2005 to 2010, BMW fitted it with the S85, a 5.0-liter V10 that spins to a ridiculous 8,250 rpm and makes 500 hp, and it remains the only V10 the company has ever built. The F1 connection was real, too: BMW was deep in grand prix racing then, and the road car's engine blocks were cast in the same foundry as the racing ones.

Living with it is the other half of the story. The standard gearbox was the SMG III, a single-clutch automated manual that shifts beautifully at full attack and lurches like a learner in a parking lot. American buyers, mercifully, could specify a proper six-speed manual. Add the rod bearings, the thirst, and the repair bills, and you get the E60's reputation as a glorious money pit.

None of that has dented the appeal, because nothing else sounds remotely like it. As a bit of trivia, slicing two cylinders off this V10 is basically how BMW arrived at the V8 in the E90 M3. The E60 is the most dramatic M5 ever built and the least compromising. It is, perhaps, the most guilt-inducing sedan money can buy... a mistake I hope to one day make.