When Mercedes-Benz introduced its new C-Class sedans last year, the cars earned eight major American automotive awards, appealing to groups as diverse as AAA,Automobile magazine, the North American Car of the Year jury and the numbers-conscious IntelliChoice, which called the Mercedes-Benz C220 the best overall value in luxury cars under $40,000. In large part, the cars' appeal was due to the low (for Mercedes) price tag. The all-new cars, which replaced Mercedes' entry-level 190 series, were bigger and more powerful, and yet came in at about the same price. These cars were the first fruits of a new production system that proved to be more efficient than Mercedes' previous efforts. Buyers responded, and the C-Class cars are selling in greater numbers than the 190 models ever did, with sales limited primarily by availability. For 1995, the 4-cylinder C220 and the 6-cylinder C280 continue virtually unchanged. Prices are $31,425 for the C220 and $36,775 for the C280, but their core virtue - a rock-solid Mercedes at a competitive price - continues.