BMW's 4-Series Coupe concept is essentially the vehicle that will replace the current 3-Series Coupe. There's precedent to BMW's three-car monte number game. For example, the BMW 6-Series Coupe is essentially a 5-Series Coupe. The 3-Series will be the sedan, just like the 5-Series is. BMW says, "the "4" stands for greater sportiness, greater exclusivity and even clearer differentiation from the BMW 3 Series range."