text: In Vauban, Germany, residents of this upscale comunnity are surburban pioneers, going where few soccer moms or commuting executives have ever gone before: they have given up their cars. "When I had a car I was always tense. I'm much happier this way," said Heidrun Walter, a media trainer and mother of two, as she walked verdant streets where the swish of bicycles and the chatter of wandering children drown out the occasional distant motor.