Bob Lutz, writing today on GM's FastLane blog, discussed the Buick Invicta Concept (pictured) and its relation to the upcoming Buick LaCrosse production car. The GM CEO also gave a look into the future of GM's model-sharing plans, focusing on differentiating cars that share platforms, rather than just badge-engineering them, as GM has done in the past.

Lutz said in his post that the Invicta gives "a stront hint at what the next generation LaCrosse might look like." That's a good thing from where we sit, because the Invicta is a very handsome car. It also confirms our speculation earlier this week that the Buick LaCrosse test mule spotted by spies closely resembled the sexy concept.

It will share a platform with GM's other midsize offerings from Chevrolet, Saab, and Opel/Vauxhall. That's where the product differentiation effort comes in.

But Lutz's focus on making it very difficult to tell the various platform-sharing cars bear any relation to each other could also be good news for the maker at a time when it could really use it - GM just posted a $3.3 billion first quarter loss in North America. By developing cars with different appearances, suspensions and target markets, the company can hopefully target more segments of the market, rather than presenting essentially identical vehicles and relying on marketing to differentiate them.

Despite the greater differences in external appearance and feel, however, GM will still share internal pieces and things the customer doesn't perceive in order to maximize the savings attendant with platform sharing.

Below is a behind the scenes look at the design process for the Buick Invicta Concept.

Buick Invicta Concept

Buick LaCrosse spy shots