Small four-cylinder sedans are not commonly known for being especially quiet. However, that perception may be changing with the new crop of rides, one of which is the 2007 Nissan Sentra. We've complained about the car's weak fun factor, but there's no denying the Sentra's strength in the quiet ride category. It's expectedly shy of Lexus levels, but Nissan has done a surprisingly good job of isolating noise, and the results should impress buyers in this price class. Even when the four-banger is revved decibels are kept to a minimum, and the highway ride is downright peaceful.