Automotive designers like to say that if you’re going to steal, rob a bank, not a grocery store. Congratulations to Ford. The gorgeous new ’13 Fusion family sedan represents a successful heist. It’s fresh, new and classic all at the same time.

Some designers at competitors snarkily point out Ford is borrowing liberally from ultra-luxury auto maker Aston Martin, but Ford deserves kudos, not criticism for its execution of the Fusion.

First off, everybody steals. In the automotive world, totally unique design is overrated and hideously expensive to pull off. It’s all a matter of degree and picking the right stuff to pinch.

The Lexus LS and Hyundai Genesis and Equus tastefully borrow design elements from classic premium brands. They sell well despite critics’ complaints about derivative styling.

Meanwhile Honda’s Acura unit stubbornly blazes its own design trail and has not seen much success pleasing critics or consumers with its originality.

Cadillac’s sharp-edged Art & Science design is one of the few examples of an all-new design vocabulary becoming a long-term success at a high-volume brand, but it has taken billions of development dollars to do so and constant honing to stay in the race.

Like it or not, the best designs usually evolve over decades of trial and error. Mercedes, BMW and Aston Martin front-ends stand out because their classic shapes have long, storied histories and are proven to be successful at defining their brands and pleasing the eye.

The first-generation Taurus is remembered as having unique styling in the mid-1980s, but it borrowed from Audi’s sleek flush-glass designs of the era. Even then, many consumers first called the Taurus an ugly “jelly bean” before its striking aerodynamic lines caught the public’s fancy.

The Edsel had a unique grille design and we know how that story ended. Ditto for the Pontiac Aztek and countless other fruitless attempts at originality.

However, sometimes imitation does go beyond flattery. In a landmark 2001 case, then DaimlerChrysler sued General Motors for trademark infringement, claiming the Hummer H2’s flat, 7-slot grille was too similar to Jeep’s.

The U.S. Court of Appeals ruled design similarities between a $50,000 Hummer and a $28,000 Jeep Wrangler were not great enough to confuse consumers.

Jeep may have lost its fight with Hummer, but it did have the last laugh. Sales of the Wrangler and Grand Cherokee are soaring, while Hummer is no more.

There are unconfirmed rumors in the auto design community that there is some friction between Ford and Aston Martin, which Ford sold in 2007. But it seems unlikely anything will come of it. Aston Martins start at about $125,000, although the auto maker is selling a rebadged version of the Scion iQ for $50,000 in Europe. The current ’12 Fusion base price is $20,200. Aston Martin could not be reached for comment and Ford did not respond to an inquiry.

Is it possible Ford designers only were subconsciously aware of Aston Martin when they sketched the Fusion and Evos concept it is based on, like George Harrison when he unintentionally copied harmonies from the 1960s song “He’s so Fine” while recording his 1970 hit “My Sweet Lord”?  

Ford global design chief J Mays answered that question some years ago. A WardsAuto editor asked him if Jaguar, then owned by Ford, incorporated too much Aston Martin styling.

“You can never have too much Aston,” Mays replied.