In what must be something of a conundrum for company management, the very values that give Buicks much of their appeal to repeat customers conspire to make them nearly invisible to potential customers looking to switch from other brands. Those familiar with Buicks will instantly understand when we say these cars are understated almost to a fault, so quiet and conservative that they attract attention only in locations where automobiles normally aren't seen. Drive a Buick onto a golf course, for example, and people will notice. Otherwise, they blend into the background as unobtrusively as a finely crafted piece of furniture in a palace. To some people that's a flaw, but not to others. Glamour is nice in its own way--and Buick buyers can choose a Riviera if that's what they're looking for--but elegance, balance and a total rejection of flash and trendiness keep the cash registers ringing in Buick City. For proof of the effectiveness of Buick's philosophy, one need look no farther than the Century, one of the division's best-selling lines. The current model, totally redesigned last year, took the place of a car that sold well even at the end of a 15-year production run in which it faced such worthy opponents as the Ford Taurus, Toyota Camry, Honda Accord, Nissan Maxima and the Chrysler Cirrus and Dodge Stratus, all regularly updated while the Buick soldiered along without apparent change. The same cars are lined up against the new Century. After more than a year on the market, it has quietly carved out a solid niche for itself.