Production of the Mercedes GLA in Rastatt.

The first of the new Mercedes-Benz GLA crossovers started rolling down the maker’s assembly line in Rastatt, Germany this week, the fourth in a new array of entry-lux models that the maker hopes will give it a push past aggressive competitors like BMW and Audi.

When the GLA reaches showrooms next year, Mercedes officials hope it will follow the lead of the new CLA model that recently made its American debut. That coupe-like sedan has become the hottest offering in the maker’s U.S. portfolio, not only delivering a sizable size boost but drawing in a significant number of buyers new to the Mercedes brand.

“The GLA is the next milestone in our Mercedes-Benz 2020 growth strategy,” said Dieter Zetsche, the Mercedes brand boss and head of the maker’s parent Daimler AG.

The crossover is designed to complement the more conventional CLA and give Mercedes traction in the rapidly growing compact luxury crossover niche, which is expected to become one of the world’s fastest-growing market segments through at least the rest of the decade.

The new crossover also rounds out the broad Mercedes utility vehicle line-up which now runs from the entry-level GLA to the brutish, top-of-the-line G-Class, with the GLK, ML and GL in-between.

(New Mercedes CLA is one of the market’s “Movers” in November. Click Hereto find out who the other winners and losers were.)

As with the CLA, the new GLA crossover is targeting a lower price segment than Mercedes has normally gone after, officials saying they hope to attract buyers who would otherwise opt for more mainstream products – such as a Ford Escape or perhaps even a Toyota RAV4.  The base CLA currently comes in at just under $30,000 in the U.S.

But unlike the rock-bottom C-Class Coupe of a decade ago, Mercedes has attempted to maintain many of the luxury attributes of its more expensive models, with the use of higher-class interior materials and a more striking design than many comparable models offer.

Pricing for the Mercedes GLA has not yet been set though it’s expected to come above that of the CLA to reflect the greater content of a crossover.  Like the sedan, the GLA is expected to offer a wide range of features that could drive the base price up by thousands, even tens of thousands of dollars when fully equipped.

(Compact crossovers are commanding big-car prices. Click Here for the full story.)

The strategy appears to be working for the Mercedes CLA which has become the hottest model in the maker’s line-up since its autumn introduction.  And, according to Bernie Glaser, the maker’s U.S. marketing chief, 80% of the buyers for the coupe-like sedan have so far been drawn from competitive brands.

Both the GLA and CLA – along with the redesigned Mercedes A- and B-Class models share the maker’s new compact luxury platform.  The Stuttgart-based maker has yet to reveal what it has in the works for the fifth model off that “architecture.” In fact, that platform will ultimately find additional applications, as Mercedes is sharing it with the Renault-Nissan Alliance.

Mercedes entered into a wide and rapidly expanding partnership with the French-Japanese alliance several years ago.  Among other things, the compact luxury platform will be used for some future Infiniti models.  In turn, Renault is working up a new platform that will be used for the next-generation Twizzy microcar, as well as a new model from Daimler’s Smart brand.

Mercedes is continuing discussions, meanwhile, that could eventually see it produce one or more of its small luxury models at a new plant complex Nissan opened last month in Aguascalientes, Mexico. The partners have confirmed the talks, and plant officials showed TheDetroitBureau.com last month where they could expand to meet Daimler’s needs, but Renault/Nissan CEO cautioned that a final decision has not yet been reached.

In the meantime, the Rastatt plant will handle GLA production, along with both the A- and B-Class models.  A second factory in Kecskemét, Hungary is handling the CLA, along with overflow of the B-Class, and contract manufacturer Valmet Automotive in Uusikaupunki, Finland is expected to produce more than 100,000 A-Class vehicles between now and 2016.