No longer content to remain on the fringes of a booming luxury market, Infiniti is making bold moves to drastically improve its cars and grow its business.

A firm first step was to poach Johan de Nysschen from Audi of America last July. The South African native helped grow Audi's U.S. operations by leaps and bounds in recent years, and he will now do the same for Infiniti as the company's global president.

To make way for new vehicles and simplify the brand's confusing naming convention, Infiniti will now use Q for cars and QX for crossovers, plus double digits in increments of 10 to denote hierarchy based on vehicle price points. So, for example, the new Q50 sedan unveiled at the 2013 North American International Auto Show in Detroit used to be called the G37. The larger and pricier M56 sedan will now be called the Q70. Meanwhile, the EX37 crossover will change its name to QX50.

The letter Q takes the company back to its roots, denoting the brand's first car, the Q45 sedan, which it launched in the United States in 1989.

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2014 Infiniti Q50

What is it? The long-awaited replacement for Infiniti's G37 sedan that marks the start of a whole new design and engineering approach for Infiniti.

What's hot? It features a new design with curves and creases that look like waves in water. Details such as the shape of the front grille and the kink in the rear roof pillar will be signature cues for the brand going forward. Inside, there are cool embellishments such as aluminum trim inspired by traditional samurai armaments.

The Q50 is wider, lower and roomier than the car it replaces. It will offer two engines at launch: the latest version of Nissan/Infiniti's widely used 3.7-liter V6 rated at 328 horsepower, and a 360-horsepower hybrid system that combines a smaller V6 and an electric motor with a new design incorporating two clutches for better efficiency. A 7-speed automatic transmission and rear-wheel drive will be standard. All-wheel drive will be optional on both the regular and hybrid Q50.

The interior uses a completely new layout with two large touch screens. The upper screen is reserved for the most frequently used features, such as navigation. Only a few hard buttons will control critical functions, such as temperature setting.

De Nysschen said Infiniti will eventually add turbocharged four-cylinder and clean-diesel engines to its portfolio, but did not say whether the Q50 would get them.

What's not? As is increasingly the case with luxury cars of all kinds, the Q50 will be overflowing with new electronic technology that, in theory, should improve comfort, safety and the driving experience, but in reality runs the risk of being fussy and annoying. One example is the car's new electric power-steering system, which has four user-selectable settings that adjust the steering weight and ratio. It gives each driver more choices to tailor the car to personal preferences, but history has shown that too many choices and settings can be confusing and onerous. We will reserve judgment, though, until we get a chance to try it out.

How much and when? The Infiniti Q50 and Q50 Hybrid will go on sale in the summer. Pricing hasn't been announced, but it will probably be in line with that of the outgoing G37, which starts at $37,350.

MSN Autos' verdict: This is a hugely important car for Infiniti that will help redefine the entire company. It faces tough competition from cars such as the new BMW 3-Series and Lexus IS. The design is attractive and Infiniti's V6 has long been one of the best engines out there, so the Q50 has a lot going for it. The big question marks are just how well Infiniti has tuned the chassis dynamics and integrated all of the complicated new electronics.

Matthew de Paula wanted to be an automotive journalist ever since reading his first car magazine in grade school. After a brief stint writing about finance, he helped launch ForbesAutos.com and became the site's editor in 2006. Matthew now freelances for various outlets.