Crossovers are selling like hotcakes, and Lexus models are no exception. The RX was the brand's best-selling vehicle in the U.S. last year, and the smaller NX also experienced significant growth. Oddly enough, the rising popularity of crossovers even has one executive worried about the future of sedans.

Speaking with Automotive News, Tokuo Fukuichi hints that Lexus needs to polish up its sedan lineup. The global branding chief for Toyota Motor Corporation warns if this doesn't happen, these vehicles might not last much longer.

"Unless we can really offer a sedan experience you cannot have with an SUV or crossover, I think the sedan may not be able to survive if it does not evolve," said Fukuichi, who is also in charge of advanced design.

Lexus can bolster its sedan lineup by taking advantage of the body style's lower center of gravity, Fukuichi notes. Ensuring sedans drive like sports cars could give these vehicles an edge over their higher-riding counterparts. On the other hand, Lexus can also differentiate its sedans by making them more stylish than crossovers, a strategy that involves the use of a fastback roofline à la the Porsche Panamera. We already see some of this coupe-like styling in the new Lexus LS. Either way, the days of the classic sedan may be numbered.

"At a certain point of time, the traditional, square, three-box sedan will go away," he said.

As for wagons, the future is even more unclear. While Fukuichi said he'd like to see a wagon join Lexus, it couldn't be "just an ordinary station wagon." No plans are currently in place to introduce such a vehicle, although someday that could change.