Once upon a time, all an auto maker needed to succeed in the U.S. was bullet-proof quality and good recommendations fromConsumer Reports magazine.

Beginning in the 1970s, after being disappointed for years by sloppily built products from Detroit, buyers of mainstream vehicles were hungry for practical cars that were bolted together properly and held their value.

Even when it comes to luxury vehicles, during the past two decades, a large percentage of U.S. buyers have favored refinement over style, quiet cabins over character.

No auto maker has delivered on the promise of conservative, high-quality transportation better than Toyota. It has offered superbly engineered wheeled appliances for the masses such as the Camry and Corolla sedans and prudent luxury vehicles such as the Lexus LS, ES and RX. All these vehicles have led their segments in sales at various times, even though competitors sported more interesting sheet metal and interiors.

But Kevin Hunter, president of Toyota’s CALTY design research unit and the auto maker’s top U.S. designer, says the era of staid, sensible design is over at the auto maker. Toyota now is embarking on a new mission to create vehicles full of style and passion.

“In the past, let’s face it, we had boring design,” Hunter says during his afternoon keynote address at the WardsAuto Interiors conference last month.

So it’s out with the safe and familiar design vocabulary of the Corolla and Camry and in with shocking new ideas exemplified by concepts such as the Lexus LF-LC coupe that stunned the Detroit auto show last January.

Can a maker of sensible shoes suddenly switch gears and be successful making highly styled versions?

Toyota really does not have a choice. The wheels began falling off the Toyota juggernaut in 2009 when safety and quality issues forced a humiliating flurry of product recalls, denting the auto maker’s reputation. Then natural disasters in Japan and Thailand choked off production in Asia and the U.S. for most of 2011.

Now production is back on pace, and Toyota is making an impressive comeback, with sales up 73% in May, according toWardsAuto data.

But the automotive landscape has changed. Toyota, Lexus and Scion brands face tougher competition than ever, even in the segments they are used to dominating.

Most importantly, all brands have an unprecedented number of rivals that can boast comparable – perhaps even better – marks in third-party studies and also feature interior and exterior styling that makes Toyota iron look plain and out-of-date.

Hyundai’s “fluidic sculpture” design already is making the Camry, Corolla and Yaris look like wall flowers. Countless other mainstream models featuring strong designs, starting with the Ford Fusion, are coming. Many more in other vehicle segments are on the way or already here.

Toyota has to do something to juice up design inside and out, but it is no simple task. For decades, the auto maker’s culture has emphasized creating vehicles that are easy and efficient to manufacture, with design taking a backseat.

In his book, “Car Guys vs. Bean Counters,” former General Motors Vice Chairman Bob Lutz says GM’s problems with homely cars and look-a-like vehicles in the 1980s and 1990s stemmed from GM’s desire to imitate Toyota’s quality and manufacturing efficiency.

GM did make huge strides in these areas, but the unintended outcome for this progress was engineers and professional managers were given the authority to overrule the design department. The result, Lutz says, was vehicles that excelled at achieving internal manufacturing and budget targets but were so boring or ugly no one bought them.

If a powerful, savvy outsider like Lutz had not stepped in and put designers back in charge in 2001, it’s likely GM would have produced more disasters like the Pontiac Aztek and would not have been worth rescuing in 2009.

Toyota is not in nearly as bad shape as GM once was, but it still needs an incredibly powerful champion to foment such fundamental cultural change within the auto maker.

Fortunately, it has one. The impetus is coming directly from CEO Akio Toyoda, the highly respected grandson of the company’s founder.

If the Lexus LF-LC indicates where Toyoda is pushing design, that’s good news for Toyota and bad news for everyone else on the planet selling cars.

dwinter@wardsauto.com