New for 2008, the fourth-generation BMW M3 gets a 414-horsepower V-8. This significant because it’s the first time a series production M3 has gotten a V-8. The previous generation came equipped with a 3.2-liter, 333-horsepower six-cylinder engine. Thus the new V-8 represents a 24 percent increase in power over the previous generation six-cylinder. Base price for the M3 Convertible is $67,475, including destination and that Gas Guzzler Tax.