The positive quarterly earnings reports of retailers such as Neiman Marcus and Tiffany have confirmed that we're in the midst of a healthy economy. Now Mercedes-Benz USA (Montvale, N.J.) weighs in with its all-time best September on record. Sales of 16,952 vehicles during September 2000 were up 12.7 percent from the September 1999 sales record of 15,038. Year-to-date sales also hit an all-time record, and sales of the all-new C-Class, which launched this month, soared 35.2 percent versus September 1999 sales of the previous generation model (3,305 vs. 2,444). Following a record month in August, the E-Class was once again the volume leader, with 4,853 units sold in September, the best September on record for the E-Class and a 22.6 percent increase over September 1999 sales.