Center director Ferdinand Dudenhoeffer thinks that manufacturers use incentives and tactical registrations to inflate the KBA's statistics. The Flensburg-based KBA is the German government branch that tracks car registrations.
Dudenhoeffer said an indicator of how manufacturers manipulate sales numbers is their shares of "tactical registrations" - for example dealers' day registrations, sales to car rental agencies and registrations by the manufacturers themselves.
According to the center, the number of commercial registrations increased significantly, specifically with German manufacturers, to 59 percent in 2003 from 43 percent in 1999.
With imported brands the rate remained relatively stable at 40 percent.
The number of commercial registrations for some individual models increased substantially. During the first quarter of 2004, 79 percent of Audi A2 sales were registered as company cars, as were 80 percent of A6 sales and 70 percent of the BMW 3 series. With Ford, a high number of Ka models and Mondeos were registered as company cars, and VW pushed the Passat.
According to the center, only Mercedes had "no visible tactical registrations" during the first quarter.