To make my point, here's the history of GM's marketing triumphs and product woes, as illustrated by seven classic GM television commercials. They're short, they're entertaining, and they show how brand marketing tried to paper over GM's problems, eventually leading to the near-death of the company.
UPDATE (4/6): I added the Saturn into the mix -- probably the best example of egregiously stupid branding in the entire history of the automobile business.
PROBLEM #1: IRRELEVANT MESSAGING
This 1952 classic sets the tone for GM TV ads for the next fifty years -- associate something emotional but irrelevant (like sex or a sexy female) with the product, and then promote the product with a memorable jingle, perhaps with a patriotic subtext. While hardly unusual for brand-oriented marketing, we'll see how, in GM's case, the technique becomes increasingly absurd as the company loses its bearings.
PROBLEM #2: TOO MANY BRANDS
In this 1958 ad we see the seeds of GM's "brand-itis." The cars for all five of these brands look pretty much the same, making it unclear why they needed multiple brands. In addition, the sudden focus on the model year (absent in the 1952 ad) marks GM's implementation of "planned obsolescence." The idea was to get people to buy a new car every year by making the car so crappy that it would wear out quickly. Brand management is thus begins trumping product quality.
By 1965, GM's product quality problem is in full swing, as evidenced by this ad promoting the Corvair, which later became the subject of Ralph Nader's classic polemic: "Unsafe at Any Speed." This is the great myth of brand marketing -- you can fix problems with a lousy product with an irrelevant but emotion-laden veneer, in this case an Austin Powers-esque hottie.
As we moved into the 1970s, GM started losing what little design edge it still had. For example, the Camero, shown in this 1970 ad, was only a knock-off of the innovative Mustang. Rather than coming up with something original, GM's depended upon brand marketing to create an identity. Once again the company tries flogging the "cars are sexy" angle, but the resulting ad is increasingly creepy, almost as if he's about to start humping the car.
As GM proceeded into the 1980's, Japanese car manufacturers began to clean GM's clock. Rather than building cars that were better than comparably-priced Japanese models, GM attacked the problem by (surprise!) launching a new brand. Hilarious, the "brand message" of the Saturn wasn't that the cars were higher quality than the Japanese competition, but that the Saturn sales staff weren't jackasses, apparently unlike those of GM's other brands.
As Japanese manufacturers continued to steal GM's market share, GM could have fixed their quality problems. Instead, they trapped back to what they knew best: brand marketing. They positioned their products as "patriotic" in an attempt to get customers to buy GM rather than Japanese. Ironically, it was about this time that GM started moving its manufacturing overseas -- not to create better cars, but to create better margins. They were essentially screwing the blue collar workers to whom their patriotic ads were supposed to appeal. Only the extremely gullible were fooled.
As GM moved into the current decade, it began trying to fix its brand image as a company that made substandard cars. As engaging as this Superbowl ad might be, it can't address the problem because the problem isn't perception of present reality (GM's cars did improve their quality) but the long standing memory of reality (the decades of crap). What's worse, putting a "spotlight" on quality merely served to emphasize that it wasn't there to start with. Sad. So sad.
So there you have it. Rather than fixing the fundamental problems in the company and its products, GM tried to brand market its way to continued success. It didn't work because it never works. While there is sometimes a lag time, a bad product always leads to a bad brand. And vice versa.