Cars are not elevators, says designer Chris Bangle. They need to have "an emotional relevance".
After the success, comes the backlash. In terms of design, his latest saloon, showcasing BMW's new styling direction, is one of the most controversial products in automotive history. Since the launch of the new 7 Series, design chief Chris Bangle has become the most talked-about car designer in the world.
To his detractors, he is a shameless artist messing with success and misappropriating BMW's hard-won intellectual property. To his supporters he is a creative genius.
Few people in the public eye have engendered such polarised opinions about their work. He is the butt of caustic online and media criticism. One website has initiated a petition to his employers to sack him or, if not, to "escort him to the typing pool".
At the same time US-based Automobile magazine has just chosen him as the Automotive Man of the Year for daring to be different, and selected the new BMW Z4 sports car as its Design of the Year. The Economist magazine also counters that Bangle is right with the 7 Series and his detractors are wrong.
US-born Bangle has been responsible for design at BMW since 1992. Before that he was director of Fiat Design where he was involved in the development of the Fiat Coupe and the Alfa Romeo 145. Art school educated, the 46-year old trained as a Methodist minister before embracing the material world of car design. He now leads a team of 250 including design engineers, artists and specialists in colour and ergonomics.
Most of the recent debate relates to the new 7 Series, the first example of BMW's new generation of designs. The look of the new saloon was part of an internal competition between 12 design teams under Bangle's guidance. Out of 12 entries, three were selected, refined and leveraged before one was chosen and approved by the board.
BMW takes the view that premium products should be radically re-designed every 14 years. Once introduced, a design works for about seven years. It is then slightly revised for a second seven-year term after which it should be revolutionised.
Critics of the new 7 Series have wondered how it could drive so well but look so bad - the car got praise for virtually everything except styling. Some letters to editor pages questioned how one could "lust after a car that looked so damn ugly in broad daylight".
Bangle's team seems to have moved the 7-Series away from the classic BMW wedge-shape. They reshaped the rear by raising the boot lid and widened its opening.
The front direction indicators have been built, eye-brow like, into the upper edges of the headlights, which also appear in spy-shots of the new 5 Series, and the saloon has iDrive, a screen-based system on the dashboard where one button controls a myriad of functions by scrolling through various menus.
It's clear that the negative reaction to the design disappoints Bangle. Conformity, he says, attracts less media attention.
"Standing out strikes fear. We don't do stuff to freak people out. We take a long-term view. The difficulty is when it's not a dialogue but a one-sided exhortation of pent-up frustration that the past hasn't stayed still. It would be hard to call it an exchange of views."
But, despite the passion it ignites, he believes that "cars should be emotionally relevant - it would be terrible if they got no response at all".
Bangle rushes in particular to the defence of the new saloon. "It's a damn nice car," he says watching one pull out of the car park. And, love or hate the rear styling, the car has enormous presence. "The new car had to be different for functional reasons and to create a high performance sports saloon. It's taller than the previous model. This gives greater interior space and allows us to stiffen the chassis which means safer driving and greater safety in an accident.
"A different profile also means you have to look at aerodynamics to get the right downforce to make it safe when cornering. We had to give it a new rear which had to be higher for aerodynamics. But when you do new things, you have to give people time to connect."
About the iDrive, which is likely to be incorporated in a simpler fashion into other models, he says: "There's nothing we do with regrets. We learn and move forward."
Bangle claims that, unlike its predecessor, the new 7 Series is a global car which is what all car companies aspire to creating. The new car is selling more than its predecessors - "so in these terms alone, it's a success".
This has led Automobile magazine to remark that those who can afford it care less than those who can't, though obviously the emotion is also coming from many who wonder how the new look will filter down to other models.
The designer has also put his mark on the Z4 that is as much talked-about as the qualities of the car itself. Costing $1 billion and dubbed "flame surfacing", the car's surface with its concave lines looks as if it was hewn by flames. The sports car looks ultra-modern and the design has a huge "wow" factor.
For Bangle, the new models represent milestones in contemporary car design although he openly admits that the 7 Series and the Z4 "have had a very hard job of playing the show". The new 5 Series "will be right in the middle, nothing unusual or unexpected".
It's obvious that the mass of response has made its mark. He is a politically correct interviewee. Unlike Renault's Patrick Le Quement who once said about the Mondeo that he couldn't sleep at night if he had designed "that car", Bangle is not easily drawn on designs beyond BMW. He believes that, for the most part, design changes are slow and incremental with few companies touching more than the head-lights.
He admires Renault for pushing the boat out and, on innovations such as the Fiat Multipla, he merely says the design came very close to brief. "The Japanese are competent car builders - it's not so easy to see design leadership, though they make tonnes of unusual product for their local market."
Bangle believes that any car is part of its time but the best designs set the trend and offer something. "They are part of the movement if the designer is doing his job well. Good design is making the movement happen."
The designer who himself drives a 740d argues that design is less than 1 per cent of total costs when you take account of plant, equipment, sales and manufacturing. "It's peanuts in the whole deal and is not a drag on the system."
Ultimately the market will decide. In Germany annual production of the 3-series is third only to the Opel Astra and the Golf, according to recent research. In effect, BMW piles them high and sells them expensively, a recipe for high margins and profits, to which styling is an important contributor.
Time will tell but the success of BMW's ambitious line-up over the next few years - revised 5 Series, new 6 Series, X3 and 1 Series - will be influenced by its new design direction. Supporters of Bangle claim that his work will be hugely influential and will bear another of the hallmarks of success - imitation by competitors.
What of car designs of the future? "You have to look at the role of the car in the context of people's lives," he says. "Will the car become the most interesting phenomenon of the last century? Hopefully a car won't change from something emotional to merely being a carrier of people from a to b. That's what an elevator does." Unlikely, if Bangle has anything to do with it.