Odd numbers are for sedans while even numbers are for coupes. The 4 Series replaces the long-running 3 Series Coupe, as well as 3 Series Convertibles. While most will think it's merely a 3 Series with the rear doors taken out, the 4 Series is actually lower, slightly longer and wider than its four door brother. This promises a more planted, sportier drive and further differentiates it from its four door sibling. Available in diesel 420d or gas 428i, this coupe promises joy behind the wheel.