Porsche's least-expensive convertible is offered with only minor changes for 2005, in base and S trim levels. A 225-horsepower, 2.7-liter six-cylinder engine, coupled to a five-speed manual transmission, comes standard, while the S receives a 258-horsepower, 3.2-liter six-cylinder powerplant and a six-speed manual gearbox. Read full reviews here.